The document provides information on various machining operations including turning, boring, shaping, milling, grinding, finishing operations, and design of jigs and fixtures. It discusses the calculations of material removal rate, power required, and cutting time for these operations. It provides examples to calculate cutting speed, feed rate, depth of cut, cutting time, power required, and number of times a cutting tool must be resharpened for specific turning and milling jobs. The document also summarizes the mechanics and calculations for other machining processes like shaper, grinding, and boring.
This document discusses various types of boring machines and their uses. It describes horizontal and vertical boring machines, floor type boring machines, turret type boring machines, and precision jig boring machines. It also discusses boring bars and tool holders, including adjustable, damped, and line boring bars as well as boring and facing heads. Jig boring machines resemble vertical milling machines and are designed for accuracy through rigidity and precise measurement capabilities.
The document discusses the mechanics of metal cutting. It covers topics such as cutting models, turning forces, power and energies, tool terminology, cutting geometry, material removal rate, orthogonal and oblique cutting models, turning and facing forces, velocities, cutting forces, the merchant's circle diagram, stresses, power, specific cutting energy, and violations of orthogonal cutting models. It provides the theoretical framework for understanding metal cutting and machining processes.
The document defines jigs and fixtures, their purposes and key differences. Jigs hold and guide tools during machining operations while fixtures only hold workpieces. Both aim to provide repeatability, accuracy and interchangeability in manufacturing. The document also describes various types of jigs and fixtures used for different machining processes like turning, milling, grinding and their elements.
The document provides information about shaping and planing processes. It discusses the shaping machine, including its principal parts like the base, column, ram and tool head. It describes the shaping operations of producing flat surfaces, slots and contours. The quick return mechanism is explained, along with specifications, tool materials and cutting motions. Formulas for cutting speed, feed, depth and machining time calculations are also presented.
Gear finishing processes are necessary to produce accurate, smooth gear teeth after initial formation. The main gear finishing processes are gear shaving, burnishing, grinding, lapping, and honing. Gear shaving involves running a gear against a cutter to scrape off irregularities. Gear burnishing plastically moves excess material during rolling. Gear grinding is the most accurate but also the most expensive method. Lapping and honing use abrasives to remove burrs and irregularities from heat treated gears in a faster process than other methods.
Broaching is a machining process that uses a toothed tool called a broach to remove material in a single pass. Broaching was first used in the 1850s and was commonly used to rifle gun barrels during World War 1. Broaching machines can perform horizontal, vertical, continuous, and rotary broaching. Broaching tools are designed based on the material, size and shape of the cut, required tolerances, and production rates. Broaching provides high production rates and accuracy for complex hole shapes and surfaces.
This document discusses magnetic abrasive finishing (MAF) as a micro/nano finishing process for advanced materials like ceramics. MAF uses magnetic abrasive particles composed of ferromagnetic material and abrasive grains to remove material in the form of microchips. It provides a concise overview of how MAF works, the mechanisms of material removal, key parameters that affect the process, and applications for finishing ceramics. Experimental results show MAF can produce very smooth surfaces down to the nano-scale on ceramics with no microcracks or residual stresses.
This document discusses various types of boring machines and their uses. It describes horizontal and vertical boring machines, floor type boring machines, turret type boring machines, and precision jig boring machines. It also discusses boring bars and tool holders, including adjustable, damped, and line boring bars as well as boring and facing heads. Jig boring machines resemble vertical milling machines and are designed for accuracy through rigidity and precise measurement capabilities.
The document discusses the mechanics of metal cutting. It covers topics such as cutting models, turning forces, power and energies, tool terminology, cutting geometry, material removal rate, orthogonal and oblique cutting models, turning and facing forces, velocities, cutting forces, the merchant's circle diagram, stresses, power, specific cutting energy, and violations of orthogonal cutting models. It provides the theoretical framework for understanding metal cutting and machining processes.
The document defines jigs and fixtures, their purposes and key differences. Jigs hold and guide tools during machining operations while fixtures only hold workpieces. Both aim to provide repeatability, accuracy and interchangeability in manufacturing. The document also describes various types of jigs and fixtures used for different machining processes like turning, milling, grinding and their elements.
The document provides information about shaping and planing processes. It discusses the shaping machine, including its principal parts like the base, column, ram and tool head. It describes the shaping operations of producing flat surfaces, slots and contours. The quick return mechanism is explained, along with specifications, tool materials and cutting motions. Formulas for cutting speed, feed, depth and machining time calculations are also presented.
Gear finishing processes are necessary to produce accurate, smooth gear teeth after initial formation. The main gear finishing processes are gear shaving, burnishing, grinding, lapping, and honing. Gear shaving involves running a gear against a cutter to scrape off irregularities. Gear burnishing plastically moves excess material during rolling. Gear grinding is the most accurate but also the most expensive method. Lapping and honing use abrasives to remove burrs and irregularities from heat treated gears in a faster process than other methods.
Broaching is a machining process that uses a toothed tool called a broach to remove material in a single pass. Broaching was first used in the 1850s and was commonly used to rifle gun barrels during World War 1. Broaching machines can perform horizontal, vertical, continuous, and rotary broaching. Broaching tools are designed based on the material, size and shape of the cut, required tolerances, and production rates. Broaching provides high production rates and accuracy for complex hole shapes and surfaces.
This document discusses magnetic abrasive finishing (MAF) as a micro/nano finishing process for advanced materials like ceramics. MAF uses magnetic abrasive particles composed of ferromagnetic material and abrasive grains to remove material in the form of microchips. It provides a concise overview of how MAF works, the mechanisms of material removal, key parameters that affect the process, and applications for finishing ceramics. Experimental results show MAF can produce very smooth surfaces down to the nano-scale on ceramics with no microcracks or residual stresses.
Boring machine TYPES and diagrams..from NARAYANAN L,.......AP/mechnaanmech123
This document discusses different types of boring machines used to enlarge holes through turning operations. It describes horizontal boring machines, vertical boring machines, precision boring machines, and jig boring machines. Key components of boring machines are also identified, including the bed, floor plate, base, table, column, head stock, end supporting column, and cross rail. A jig boring machine is highlighted as a precision machine used for boring accurate holes at proper center-to-center distances within a tolerance of 0.0025mm.
This document discusses laser beam machining (LBM), including:
- How lasers work by generating coherent, monochromatic light through stimulated emission.
- Common laser mediums like ruby, Nd:YAG, CO2, and their wavelengths.
- How laser light interacts with materials through absorption, melting, and vaporization.
- Key LBM process parameters like intensity, interaction time, and material properties.
- Applications of LBM like drilling, cutting, welding, and micro-machining.
1. The document discusses three common cutting tools: single point cutting tool, twist drill bit cutting tool, and plain milling cutter cutting tool.
2. For each tool, it describes the main parts and provides diagrams labeling the parts. It also discusses the common angles associated with each tool type, such as back rake angle, side rake angle, and relief angles.
3. The document provides a detailed overview of the geometry and features of these basic cutting tools.
Taper turning methods are discussed in this document. It describes different taper turning techniques used in lathe machines such as compound rest method, offset tailstock method, and taper attachment method. The document provides details on how each method works and when they should be used for turning tapers of various shapes and sizes.
The document discusses jig boring machines. It provides information on:
1) The need for jig boring machines to achieve high accuracy of hole positions and sizes that is demanded for applications like dies and fixtures.
2) The working principle of jig boring, which involves moving either the rotating tool or stationary workpiece to bore holes into the workpiece.
3) The typical construction of jig boring machines, including features like the table, saddle, column, and spindle head that provide movement capabilities.
Unit 2 Machinability, Cutting Fluids, Tool Life & Wear, Tool MaterialsMechbytes
Concept of machinability, machinability index, factors affecting machinability
Different mechanism of tool wear types of tool wear (crater, flank etc.), Measurement and control of tool wear
Concept of tool life, Taylor's tool life equation (including modified version)
Different tool materials and their applications including effect of tool coating
Introduction to economics of machining
Cutting fluids: types, properties, selection and application methods
Broaching is a machining process where a broach tool with multiple cutting teeth is pushed or pulled through a workpiece to cut it into the desired shape. Broaching provides good dimensional accuracy and surface finish. There are different types of broaching machines like horizontal, vertical pull, continuous, and rotary table machines. Broaching is used to manufacture precision components like bearing caps, gears, and splines. It provides interchangeability but the initial costs of broaches and machines are high.
This document provides information about three types of machine tools: shaper, slotter, and planer. It describes their main parts and functions. A shaper cuts flat surfaces using a reciprocating single-point cutting tool. A slotter shapes vertical surfaces in a reciprocating ram. A planer cuts flat surfaces using horizontal strokes of a cutting tool across a workpiece. The document outlines the key differences between a shaper and planer.
This document discusses various methods for manufacturing gears, including casting, forming, stamping, and machining processes like gear shaping, planing, and hobbing. It focuses on indexing methods for dividing work on a dividing head like direct indexing, simple indexing, differential indexing, and angular indexing. Key gear cutting processes covered are gear shaping using pinion cutters, gear planing using rack cutters, and gear hobbing using rotating hob cutters to progressively cut teeth.
CAPSTAN AND TURRET LATHES AND DIFFERENCES BY POLAYYA CHINTADAPOLAYYA CHINTADA
The document discusses capstan and turret lathes. It defines a capstan lathe as having a turret mounted on a ram that is mounted on the saddle, allowing the ram to provide feed to the cutting tools. Capstan lathes are lighter and provide limited feed and depth of cut. Turret lathes have the turret directly mounted on the saddle to provide feed, are heavier/more durable, and provide more feed and depth of cut for mass production of large parts. The key difference is the location of the turret - on the ram for capstan lathes and directly on the saddle for turret lathes.
This document contains lecture notes on manufacturing processes and metal cutting theory. It begins with definitions of manufacturing and an overview of various manufacturing processes. It then describes machine tools and their functions in metal cutting. Key sections cover classifications of manufacturing processes, cutting parameters like speed, feed and depth of cut, and characteristics and types of cutting tools materials. In summary, the document provides a comprehensive introduction to manufacturing processes, metal cutting theory, and machine tools.
This document discusses different types of milling operations including plain milling, face milling, angular milling, form milling, straddle milling, gang milling, end milling, and keyway milling. It provides details on each operation such as the cutters used, surfaces produced, and applications. The document is authored by Polayya Chintada who is an Assistant Professor and discusses these milling operations for a course on Metal Cutting and Machine Tools.
The document discusses various operations that can be performed on a drilling machine, including drilling, reaming, boring, counter boring, counter sinking, tapping, and spot facing. It provides brief definitions and descriptions of each operation, such as drilling produces circular holes using a rotating drill bit, reaming smooths drilled holes using a reamer tool, and tapping cuts internal threads using a threaded tap tool. The document was created by an engineering student for a class project on drilling machine operations.
Electro magnetic forming- metal spinning-peen formingPravinkumar
This document discusses three metal forming processes:
1) Electromagnetic forming uses a rapidly discharged capacitor bank to create a magnetic field that pushes and deforms a conductive metal workpiece against a die. It can form tubes and is fast with good surface finish.
2) Metal spinning forms axially symmetric parts by rotating and pressing a metal disc against a forming tool. It is suitable for low volume production of conical shapes.
3) Peen forming shoots metal shots at a sheet metal surface to induce compressive stresses and plastically deform the surface into contours, improving fatigue strength without requiring punches or dies.
Abrasive flow machining is a deburring and surface finishing process that uses abrasive particles mixed in a viscoelastic medium. It can polish internal surfaces, holes, and intersecting holes. The document discusses the need for AFM, abrasive materials used, the one-way, two-way, and orbital classification methods, process parameters like pressure and abrasive size, capabilities like surface finish ranges and tolerances, and applications in aerospace, automotive, die and mold making, and medical industries to improve surfaces, reduce wear, increase performance, and extend component life.
This grinding report summarizes two experiments conducted in a work shop. The first experiment used a surface grinding machine to grind a plate, resulting in a smooth surface finish. The second experiment used a bench grinding machine to create cutting tools for a lathe by sharpening metal plates. Bench grinders are used to drive abrasive wheels and shape metal for welding or fitting by sharpening tools like drill bits. The report provides details on the equipment, procedures, and results of the two grinding experiments.
The document discusses drilling and boring machines. It describes how drilling machines are used to produce circular holes in workpieces using rotating cutters called drills. Different types of drilling machines are described, including portable drilling machines, sensitive bench drilling machines, upright drilling machines, radial drilling machines, gang drilling machines, turret drilling machines, and deep hole drilling machines. The document also covers topics such as tool nomenclature, drilling operations, tool holding devices, work holding devices, drill types, and reaming.
A shaper machine produces flat surfaces on workpieces by moving a cutting tool in a straight line using a ram. The ram moves the tool forward for the cutting stroke and backward for the return stroke with no cutting during the return stroke. A shaper can produce horizontal, vertical, or inclined surfaces, as well as grooves, slots, and steps. The main components of a shaper are the base, column, table, cross rail, ram, and tool head. Shapers are classified based on their ram driving mechanism or orientation and include crank, geared, hydraulic, horizontal, and vertical shapers.
The document discusses cutting tool materials and Merchant's Circle Diagram (MCD) for calculating forces in machining. It provides information on 7 common cutting tool materials: high carbon steel, high speed steel, cast alloys, cemented carbides, coated carbides, ceramics, and diamonds. It also explains what MCD is and how it can be used graphically to calculate cutting, tangential, friction, normal, shear and normal shear forces from measured cutting forces. An example calculation using MCD is provided.
Machining is an essential process for finishing workpieces to desired dimensions and surface finish. A lathe allows for gradually removing excess material from a workpiece through cutting tools. Common lathe operations include turning, grooving, chamfering, parting, facing, and knurling. Taper turning can be done through methods like using a form tool, swiveling the compound rest, or a taper attachment. Thread cutting follows a helical path and involves engaging a half-nut to advance the tool.
Machining is an essential process for finishing workpieces to desired dimensions and surface finish. A lathe allows precise machining of cylindrical workpieces through various operations like turning, grooving, chamfering, parting, and facing. Key parts of a lathe include the headstock, which holds the workpiece, and the carriage, which supports the cutting tool. Common lathe accessories include centers, chucks, and rests, which provide workpiece support during machining operations.
Boring machine TYPES and diagrams..from NARAYANAN L,.......AP/mechnaanmech123
This document discusses different types of boring machines used to enlarge holes through turning operations. It describes horizontal boring machines, vertical boring machines, precision boring machines, and jig boring machines. Key components of boring machines are also identified, including the bed, floor plate, base, table, column, head stock, end supporting column, and cross rail. A jig boring machine is highlighted as a precision machine used for boring accurate holes at proper center-to-center distances within a tolerance of 0.0025mm.
This document discusses laser beam machining (LBM), including:
- How lasers work by generating coherent, monochromatic light through stimulated emission.
- Common laser mediums like ruby, Nd:YAG, CO2, and their wavelengths.
- How laser light interacts with materials through absorption, melting, and vaporization.
- Key LBM process parameters like intensity, interaction time, and material properties.
- Applications of LBM like drilling, cutting, welding, and micro-machining.
1. The document discusses three common cutting tools: single point cutting tool, twist drill bit cutting tool, and plain milling cutter cutting tool.
2. For each tool, it describes the main parts and provides diagrams labeling the parts. It also discusses the common angles associated with each tool type, such as back rake angle, side rake angle, and relief angles.
3. The document provides a detailed overview of the geometry and features of these basic cutting tools.
Taper turning methods are discussed in this document. It describes different taper turning techniques used in lathe machines such as compound rest method, offset tailstock method, and taper attachment method. The document provides details on how each method works and when they should be used for turning tapers of various shapes and sizes.
The document discusses jig boring machines. It provides information on:
1) The need for jig boring machines to achieve high accuracy of hole positions and sizes that is demanded for applications like dies and fixtures.
2) The working principle of jig boring, which involves moving either the rotating tool or stationary workpiece to bore holes into the workpiece.
3) The typical construction of jig boring machines, including features like the table, saddle, column, and spindle head that provide movement capabilities.
Unit 2 Machinability, Cutting Fluids, Tool Life & Wear, Tool MaterialsMechbytes
Concept of machinability, machinability index, factors affecting machinability
Different mechanism of tool wear types of tool wear (crater, flank etc.), Measurement and control of tool wear
Concept of tool life, Taylor's tool life equation (including modified version)
Different tool materials and their applications including effect of tool coating
Introduction to economics of machining
Cutting fluids: types, properties, selection and application methods
Broaching is a machining process where a broach tool with multiple cutting teeth is pushed or pulled through a workpiece to cut it into the desired shape. Broaching provides good dimensional accuracy and surface finish. There are different types of broaching machines like horizontal, vertical pull, continuous, and rotary table machines. Broaching is used to manufacture precision components like bearing caps, gears, and splines. It provides interchangeability but the initial costs of broaches and machines are high.
This document provides information about three types of machine tools: shaper, slotter, and planer. It describes their main parts and functions. A shaper cuts flat surfaces using a reciprocating single-point cutting tool. A slotter shapes vertical surfaces in a reciprocating ram. A planer cuts flat surfaces using horizontal strokes of a cutting tool across a workpiece. The document outlines the key differences between a shaper and planer.
This document discusses various methods for manufacturing gears, including casting, forming, stamping, and machining processes like gear shaping, planing, and hobbing. It focuses on indexing methods for dividing work on a dividing head like direct indexing, simple indexing, differential indexing, and angular indexing. Key gear cutting processes covered are gear shaping using pinion cutters, gear planing using rack cutters, and gear hobbing using rotating hob cutters to progressively cut teeth.
CAPSTAN AND TURRET LATHES AND DIFFERENCES BY POLAYYA CHINTADAPOLAYYA CHINTADA
The document discusses capstan and turret lathes. It defines a capstan lathe as having a turret mounted on a ram that is mounted on the saddle, allowing the ram to provide feed to the cutting tools. Capstan lathes are lighter and provide limited feed and depth of cut. Turret lathes have the turret directly mounted on the saddle to provide feed, are heavier/more durable, and provide more feed and depth of cut for mass production of large parts. The key difference is the location of the turret - on the ram for capstan lathes and directly on the saddle for turret lathes.
This document contains lecture notes on manufacturing processes and metal cutting theory. It begins with definitions of manufacturing and an overview of various manufacturing processes. It then describes machine tools and their functions in metal cutting. Key sections cover classifications of manufacturing processes, cutting parameters like speed, feed and depth of cut, and characteristics and types of cutting tools materials. In summary, the document provides a comprehensive introduction to manufacturing processes, metal cutting theory, and machine tools.
This document discusses different types of milling operations including plain milling, face milling, angular milling, form milling, straddle milling, gang milling, end milling, and keyway milling. It provides details on each operation such as the cutters used, surfaces produced, and applications. The document is authored by Polayya Chintada who is an Assistant Professor and discusses these milling operations for a course on Metal Cutting and Machine Tools.
The document discusses various operations that can be performed on a drilling machine, including drilling, reaming, boring, counter boring, counter sinking, tapping, and spot facing. It provides brief definitions and descriptions of each operation, such as drilling produces circular holes using a rotating drill bit, reaming smooths drilled holes using a reamer tool, and tapping cuts internal threads using a threaded tap tool. The document was created by an engineering student for a class project on drilling machine operations.
Electro magnetic forming- metal spinning-peen formingPravinkumar
This document discusses three metal forming processes:
1) Electromagnetic forming uses a rapidly discharged capacitor bank to create a magnetic field that pushes and deforms a conductive metal workpiece against a die. It can form tubes and is fast with good surface finish.
2) Metal spinning forms axially symmetric parts by rotating and pressing a metal disc against a forming tool. It is suitable for low volume production of conical shapes.
3) Peen forming shoots metal shots at a sheet metal surface to induce compressive stresses and plastically deform the surface into contours, improving fatigue strength without requiring punches or dies.
Abrasive flow machining is a deburring and surface finishing process that uses abrasive particles mixed in a viscoelastic medium. It can polish internal surfaces, holes, and intersecting holes. The document discusses the need for AFM, abrasive materials used, the one-way, two-way, and orbital classification methods, process parameters like pressure and abrasive size, capabilities like surface finish ranges and tolerances, and applications in aerospace, automotive, die and mold making, and medical industries to improve surfaces, reduce wear, increase performance, and extend component life.
This grinding report summarizes two experiments conducted in a work shop. The first experiment used a surface grinding machine to grind a plate, resulting in a smooth surface finish. The second experiment used a bench grinding machine to create cutting tools for a lathe by sharpening metal plates. Bench grinders are used to drive abrasive wheels and shape metal for welding or fitting by sharpening tools like drill bits. The report provides details on the equipment, procedures, and results of the two grinding experiments.
The document discusses drilling and boring machines. It describes how drilling machines are used to produce circular holes in workpieces using rotating cutters called drills. Different types of drilling machines are described, including portable drilling machines, sensitive bench drilling machines, upright drilling machines, radial drilling machines, gang drilling machines, turret drilling machines, and deep hole drilling machines. The document also covers topics such as tool nomenclature, drilling operations, tool holding devices, work holding devices, drill types, and reaming.
A shaper machine produces flat surfaces on workpieces by moving a cutting tool in a straight line using a ram. The ram moves the tool forward for the cutting stroke and backward for the return stroke with no cutting during the return stroke. A shaper can produce horizontal, vertical, or inclined surfaces, as well as grooves, slots, and steps. The main components of a shaper are the base, column, table, cross rail, ram, and tool head. Shapers are classified based on their ram driving mechanism or orientation and include crank, geared, hydraulic, horizontal, and vertical shapers.
The document discusses cutting tool materials and Merchant's Circle Diagram (MCD) for calculating forces in machining. It provides information on 7 common cutting tool materials: high carbon steel, high speed steel, cast alloys, cemented carbides, coated carbides, ceramics, and diamonds. It also explains what MCD is and how it can be used graphically to calculate cutting, tangential, friction, normal, shear and normal shear forces from measured cutting forces. An example calculation using MCD is provided.
Machining is an essential process for finishing workpieces to desired dimensions and surface finish. A lathe allows for gradually removing excess material from a workpiece through cutting tools. Common lathe operations include turning, grooving, chamfering, parting, facing, and knurling. Taper turning can be done through methods like using a form tool, swiveling the compound rest, or a taper attachment. Thread cutting follows a helical path and involves engaging a half-nut to advance the tool.
Machining is an essential process for finishing workpieces to desired dimensions and surface finish. A lathe allows precise machining of cylindrical workpieces through various operations like turning, grooving, chamfering, parting, and facing. Key parts of a lathe include the headstock, which holds the workpiece, and the carriage, which supports the cutting tool. Common lathe accessories include centers, chucks, and rests, which provide workpiece support during machining operations.
This document provides information about lathe operations including turning, facing, knurling, grooving, parting, chamfering, taper turning and drilling. It describes the main parts of a lathe like the headstock, tailstock, carriage. It discusses workholding devices, cutting conditions, and formulas to calculate cutting speed, feed rate, depth of cut, material removal rate and machining time. It also includes examples to demonstrate calculations for these parameters.
The document discusses shaping, planing, and slotting operations. It describes the motions and machine tools used for producing flat surfaces, including the main parts and operations of shapers and planers. Shapers use a reciprocating tool motion while planers use a reciprocating worktable. Examples are provided to calculate machining time and material removal rate for specific jobs on a shaper and planer.
This document provides information about shaping, planning, and slotting operations. It discusses the differences between these processes and the machines used. Shaping and slotting involve reciprocating the tool while feeding the workpiece, while planning involves reciprocating the workpiece and feeding the tool. Examples of shaping machines include horizontal and vertical shapers. Key parameters that affect machining include cutting speed, feed, depth of cut, and material removal rate. Example calculations are provided to determine machining time and cost for specific shaping operations.
Shaping, planing and slotting operationssabry said
This document provides information about shaping, planning and slotting operations. It discusses the key differences between these processes, describes the machines used such as shapers and planers, and covers operating conditions like cutting speed, feed, depth of cut, and material removal rate. It also includes examples of problems calculating machining time and cost for specific shaping and planning jobs.
This document provides information about the Workshop Practice course offered by the Mechanical Engineering department at Landmark University. The key points are:
- The course covers workshop safety, fitting and measurement, sheet metal work, lathe work, milling, plastic technology training, CAD/CNC machining, and hands-on experience with workshop equipment.
- It discusses various machining operations like turning, drilling, boring, that are performed in a machine shop. Formulas to calculate machining times for different operations like turning, threading, and tapping are also provided.
- Examples are given to demonstrate how to estimate machining times for operations like turning, drilling, facing, using data like cutting speed, feed rate
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
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journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals
this is 2nd presentation of manufacturing processes in this presentation we discuss in detail about the theory of metal cutting, machiening processes,cutters etc
This document discusses the theory and relationships involved in metal machining processes. It covers the basics of chip formation and cutting tool geometry, defines the key forces and stresses in machining, and derives the fundamental Merchant equation relating cutting forces and tool geometry. It also provides equations for calculating shear strain, shear stress, cutting power requirements, and the influence of tool geometry on forces and chip removal. Overall, the document establishes the theoretical foundations for understanding and analyzing metal cutting operations.
a cutting tool or cutter is any tool that is used to remove material from the work piece by means of shear deformation. Cutting may be accomplished by single-point or multipoint tools. Single-point tools are used in turning, shaping, planing and similar operations, and remove material by means of one cutting edge. Milling and drilling tools are often multipoint tools. Grinding tools are also multipoint tools. Each grain of abrasive functions as a microscopic single-point cutting edge (although of high negative rake angle), and shears a tiny chip
This document summarizes turning operations on a lathe. It describes the basic components of a lathe like the bed, headstock, tailstock, and carriage. It explains various turning operations including turning, facing, cutting with form tools, boring, drilling, parting, threading, and knurling. It also discusses tool geometry, material removal rate calculations, forces during turning, tool materials and speeds, workholding devices, and cutting fluids. Turning is a versatile machining process where the workpiece is rotated while being cut to produce various axisymmetric shapes.
Turning is one of the most basic machining processes where a part is rotated while being machined. Lathes are versatile machines capable of producing a variety of shapes through processes like turning, facing, cutting, boring, drilling, parting, threading, and knurling. The material removal rate in turning depends on factors like the cutting speed, depth of cut, and feed rate. Forces on the cutting tool include the cutting force, thrust force, and radial force. Tool geometry, workpiece material, and cutting conditions must be selected appropriately for different operations.
This document provides an overview of fundamental machining processes including turning, milling, drilling, broaching, and shaping. It discusses key concepts such as chip formation, cutting forces, tool angles, friction at tool-chip interfaces, and sources of chatter vibration. Examples are provided to calculate speeds, feeds, cutting times, and metal removal rates for different machining setups and operations.
Machining processes involve removing excess metal from a workpiece through plastic deformation using a cutting tool. There are two main types of machining: metal cutting and machining. Metal cutting involves removing a thin chip through plastic deformation. Machining involves various material removal processes. The mechanics of machining involve plastic deformation and shear to form continuous chips. Cutting forces are generated through shear and friction and depend on cutting conditions and tool geometry. Chips can be discontinuous, continuous, or continuous with a built-up edge depending on conditions. Cutting temperature also increases with cutting speed and affects tool wear.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document presents a study on modeling and analyzing a surface milling cutter using finite element analysis. The study involves designing a face milling cutter using CATIA V5 software. A single tooth of the cutter is then modeled and analyzed in ANSYS for different spindle speeds ranging from 50 to 2000 rpm. The stresses acting on the tooth are calculated and compared with theoretical values. The stress values obtained from finite element analysis match well with theoretical calculations. The study demonstrates an integrated approach for computer-aided design and analysis of milling cutters.
The document provides information about lathe operations including turning, facing, knurling, grooving, parting, chamfering, taper turning and drilling. It discusses lathe components like the bed, headstock, tailstock, carriage and feed screw. It also covers workholding devices, operating conditions, material removal rate, process sequences and examples of calculating machining times and tool life.
This document provides information about milling machines and milling operations. It defines milling as a machining process where material is removed from a workpiece using a revolving cutting tool. Various types of milling machines are described, including horizontal milling machines, vertical milling machines, and universal milling machines. Milling cutters, indexing, and other related topics are also summarized. The document aims to explain the basic concepts and components involved in milling processes.
The intern summarized key details from an internship document at LMTG:
1. The intern conducted two projects - developing a specialized tool for back spot facing an ash lock, and analyzing surface finish obtained from a wiper cutter on a horizontal boring machine.
2. For the first project, the intern proposed and tested solutions to challenges like tool length and vibrations. This included a stepped shaft design.
3. For the second project, the intern conducted trials varying machine, cutter, and parameters, finding spindle runout caused back cutting on one machine.
theory of metal cutting assignment problemsR PANNEER
The document contains 7 questions related to metal cutting practices and calculations involving cutting speed, feed rate, shear angle, chip thickness, cutting forces, friction forces, power requirements, and production time. Specific calculations are asked to determine motor power, cutting time, drilling power, milling cutter offset, and total production time for machining various metals like mild steel, C-20 steel, and AISI-304 steel. Shear angle, chip reduction coefficient, forces, and energy are to be calculated using given tool geometries and machining conditions.
Falcon stands out as a top-tier P2P Invoice Discounting platform in India, bridging esteemed blue-chip companies and eager investors. Our goal is to transform the investment landscape in India by establishing a comprehensive destination for borrowers and investors with diverse profiles and needs, all while minimizing risk. What sets Falcon apart is the elimination of intermediaries such as commercial banks and depository institutions, allowing investors to enjoy higher yields.
In a tight labour market, job-seekers gain bargaining power and leverage it into greater job quality—at least, that’s the conventional wisdom.
Michael, LMIC Economist, presented findings that reveal a weakened relationship between labour market tightness and job quality indicators following the pandemic. Labour market tightness coincided with growth in real wages for only a portion of workers: those in low-wage jobs requiring little education. Several factors—including labour market composition, worker and employer behaviour, and labour market practices—have contributed to the absence of worker benefits. These will be investigated further in future work.
How Does CRISIL Evaluate Lenders in India for Credit RatingsShaheen Kumar
CRISIL evaluates lenders in India by analyzing financial performance, loan portfolio quality, risk management practices, capital adequacy, market position, and adherence to regulatory requirements. This comprehensive assessment ensures a thorough evaluation of creditworthiness and financial strength. Each criterion is meticulously examined to provide credible and reliable ratings.
Vicinity Jobs’ data includes more than three million 2023 OJPs and thousands of skills. Most skills appear in less than 0.02% of job postings, so most postings rely on a small subset of commonly used terms, like teamwork.
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1. Unit-II
• Machine tools and machining operations for
Turning
Boring
Shaping
Milling
Grinding
– Calculation of MRR, Power required and Cutting time
•Finishing operations
•Surface treatment
•Coating and cleaning
•Design of Jigs and Fixtures
•Design of press working tools
9. 1. A cylindrical stainless steel rod with length L=150 mm,
diameter Do = 12 mm is being reduced in diameter to Df =11
mm by turning on a lathe. The spindle rotates at N = 400
rpm, and the tool is travelling at an axial speed of υ=200
mm/min
Calculate:
a. The cutting speed V (maximum and minimum)
b. The material removal rate MRR
c. The cutting time t
d. The power required if the unit power is estimated to 4
w.s/mm3
10. SOLUTION:
a. The maximum cutting speed is at the outer diameter Do
and is obtained from the expression V = π DoN
Thus,
Vmax = (π) (12) (400) = 15072 mm/min
The cutting speed at the inner diameter Df is
Vmin = (π) (11) (400) = 13816 mm/min
b. From the information given, the depth of cut is
d = (12 – 11) / 2 = 0.5 mm , and the feed is f = υ / Ν
f = 200 / 400 = 0.5 mm/rev
thus the material removal rate is calculated as
MRR = (π) (Davg) (d) (f) (N) = (π) (11.5) (0.5) (0.5) (400) = 3611 mm3
/min = 60.2 mm3 /s
c. The cutting time is
t = l / (f. N) = (150) / (0.5) (400) = 0.75 min
d. The power required is
Power = (4) (60.2) = 240,8 W
11. 2. The part shown below will be turned in two machining steps.
In the first step a length of (50 + 50) = 100 mm will be reduced
from Ø100 mm to Ø80 mm and in the second step a length of
50 mm will be reduced from Ø80 mm to Ø60 mm. Calculate
the required total machining time T with the following cutting
conditions:
Cutting speed V=80 m/min,
Feed is f=0.8 mm/rev,
Depth of cut = 3 mm per pass.
12. SOLUTION:
V=80 m/min
f=0.8 mm/rev
The turning will be done in 2 steps. In first step a
length of (50 + 50) = 100 mm will be reduced from
Ø100 mm to Ø80 mm and in second step a length
of 50 mm will be reduced from Ø80 mm to Ø60 mm
13.
14. 3. The shaft shown in the figure below is to be
machined on a lathe from a Ø 25mm bar.
Calculate the machining time if speed V is 60
m/min., turning feed is 0.2mm/rev, drilling
feed is 0.08 mm/rev and knurling feed is 0.3
mm/rev.
15. Step 2
Turn Ø20 mm from Ø25 mm
Tm = L/FN
= 45/0.2 x 764
= 0.29 min
16.
17. 4. A batch of 800 workpieces is to be produced on a
turning machine. Each workpiece with length
L=120mm and diameter D=10mm is to be
machined from a raw material of L=120mm and
D=12mm using a cutting speed V=32 m/min and a
feed rate f=0.8 mm/rev. How many times we have
to resharpen or regrind the cutting tool?
In the Taylor’s expression, use constants as n=1.25
and C=175.
27. Slab-milling operation, in which a rotating cutting
tool removes a layer of material from the surface
of workpiece.
End-milling operation, in which a rotating cutter
travels along a certain depth in the workpiece and
produces a cavity.
38. Up milling and
down milling
• When the feed and the cutting
action is in the opposite direction
the operation is called up milling.
• When the feed and cutting
action are in the same
direction the operation is
called down milling.
• In down milling there is
tendency of the job being
dragged into the cutter, up
milling is safer and commonly
done.
• However down milling results
in a better surface finish and
longer tool life.
39. The scheme of chip formation during plain slab milling using a straight
cutter is shown in the figure.
D= Diameter of the cutter N= rpm of the cutter
d=depth of the cut f= feed velocity
40. Since all the cutting
edges take part in
machining, a study of the
process is facilitated by
considering the action of
only a single tooth.
If
f= feed velocity of a
table in mm/min
Then effective feed per
tooth in mm is f/NZ
N= cutter rpm
Z= number of teeth in
the cutter
Material removal rate per unit width= f d
λ
λ
41. It is seen from the figure
that the thickness of the
uncut material in front of
the cutting edge
increases gradually,
reaching a maximum
near the surface, and
again drops to zero
quickly.
If feed velocity is small as
compared with the
circumferential velocity
of the cutter then,
AB=AC Sin λ or
t1max = (f/NZ) Sin λ
Where
λ =angle included by the contact arc at
the cutter center O in radians
λ
λ
42. Consider triangle
OAT
Cos λ = OT/OA =
(D/2 – d)/ D/2
Hence
Sin λ = (1- Cos2 λ)1/2
= [1- (1-2d/D)2]1/2
= 2 (d/D) 1/2
Neglecting the higher order terms in d/D as it is normally very small.
Using this value of Sin λ in the expression of maximum uncut thickness we get
t1max = (f/NZ) Sin λ
t1max = 2f/NZ (d/D) 1/2
λ
λ
43. The cutting force
components FC and FT not
only change in direction
but also in magnitude as
the cutting edge moves
along the cutting surface.
When cutting with straight
cutter, there is no
component of the cutting
force along the cutter axis.
The average uncut
thickness can be taken as
half of the maximum value.
t1max = 2f/NZ (d/D) 1/2
t1av = f/NZ (d/D) 1/2
44. The average values FC
and FT can be
approximately found
using the average value
of uncut chip thickness.
Since FT acts in the
radial direction , it does
not produce any torque
and the arbor toque is
due to the component
FC.
Mmax = FC (D/2).
M= torque due to one
cutting tooth and varies
approximately as FC.
• The above figure shows the variation of
arbor torque with arbor rotation for the
action of only one single tooth.
• Now to get the over all torque (M ), the
moments due to all the teeth should be
properly superimposed. This leads to
three different possibilities.
1) λ<2π/Z 2) λ =2π/Z 3) λ >2π/Z
λ
λ
45. The figure shows the three
different possibilities, the
arbor torque corresponding
to each of the these are
shown.
The machining power can
be calculated by taking the
product of the arbor speed
and the average overall
arbor torque.
The average thrust force can
be considered to be acting
along the midradial line of
the work-cutter contact arc.
λ
λ
λ
λ
λ
λ
46. tm=Machining time = (lw +a)/f
lw = Length of the workpiece
a= approach length= [d(D-d)] 1/2
47. • Q: A mild steel block of 20mm width is being milled
using a straight slab milling cutter with 20 teeth,
50mm diameter and 10 degree radial rake. The feed
velocity of the table is 15mm/min and the cutter
rotates at 60 rpm. If the depth of cut of 1mm is used,
what will be power consumption. (Assume
coefficient of friction=0.5, and shear stress=400
N/mm2 .
48. • Q: Estimate the power required during the up
milling of a mild steel block of 20mm width using
straight slab milling cutter with 10 teeth, 75mm
diameter, and 10 degree radial rake. The feed
velocity of the table is 100mm/min, the cutter
rotates at 60 rpm and the depth of cut is 5mm.
55. The cutting operation
in shaper is
intermittent in nature
and takes place during
the forward stroke.
During the return of
the tool the feed
motion is is provided
when there is no
cutting action.
In an actual cutting
operation the major
parameters are:
N= Stroke per unit
time
S= Stroke length
R= Quick return ratio (displacement/stroke)
D= depth of cut and the tool angles.
56. The uncut thickness
and width of the cut
is given by the
relations
t1 = f cosψ
w=d / cosψ
Ψ = primary
principal cutting
edge angle
α = normal rake
angle
57. The figure shows the
cutting and thrust
components of the
force.
The cutting
components Fc
acts against v and FT
acts perpendicular to
the transient surface.
FT can be resolved into
two components Ff
(feed component) and
Fn (component normal
to the machined
surface)
Ff =FT cosψ
Fn =FT sinψ
MRR= LdfN
L= length of the job
N= number of cutting strokes per unit time
58. The cutting time is given by
Tm H/d x B/f x 1/N
B=breadth of the job
H= the total depth by which the work surface to be lowered
d= depth of cut
f=feed
N=cutting stroke per unit time
Since the cutting speed changes during the cutting stroke, the average
cutting speed v is given by
v=[NS(1+R)]/2
where
S=stroke length
R= quick return ratio
N= number of strokes per unit time
59. • Q: Determine the three components of the
machining force when shaping a cast iron block
with depth of cut = 4mm, feed= 0.25 mm/stroke,
normal rake angle of the tool= 10 degree,
principal cutting edge angle=30 degree,
coefficient of friction between chip and tool=0.6,
and ultimate shear stress of cast iron=340N/mm2
.If the operation takes place with 60
stroke/min,what will be the power consumption if
the length of the job is 200mm.
61. Grinding
• It is the process of removing material by the abrasive action of
revolving wheel from the surface of the work piece, in order to
achieve required dimension and surface finish.
• The wheel used for this purpose is called grinding wheel.
• Grinding wheel consists of sharp grains called abrasives held
together by bonding material.
• The grains actually taking part in the material removal process
are called the active grains.
• Generally the sharp edges of the grains wear out and become
blunt.
• This results in large forces on the active grains during
machining.
• When the cutting edge is too blunt and the force is sufficiently
high, the grain may either get fractured or break away from the
wheel.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
82. Mechanics of grinding
• In the analysis of grinding process, all grains are assumed to be
identical.
• Two different types of grinding operations namely plunge grinding
and surface grinding will be considered for analysis.
• In plunge grinding operation a job of rectangular cross-section is
being fed radially at the feed rate f (mm/min).
• The uncut chip thickness per grit ( t1 ) can be expressed as
t1 = f/ZN.
Z=number of active grains per revolution in one line
N=rpm of the wheel
83. b‘ = average grain width of cut in mm
t1 = uncut thickness per grit
84. The number of grains /revolution/line (Z) is given
by:
Z=πDC b'
D = diameter of the grinding wheel
b‘ = average grain width of cut in mm
C = the surface density of active grains (mm-2
Also
t1 = f/πDC b‘ N
t1 = [f/πDNC rg]1/2
rg can take the value between 10 and 20
The uncut sections have approximately triangular cross
section. The ratio rg =b‘/ t1 since b‘= t1 rg
85. Once t1 is estimated, the value of specific energy UC can
be determined and the power consumption is
W= A f UC /60
• A= cross section area of the job (mm2)
Force per single grit
Fc = 60000 W/ πDACN
Fc = [1000 f UC / πDCN] N
Uc = Uo t1
-0.4 Uo depends on materials, for
steel it is 1.4.
MRR= lxbxf mm3
86. • Q: Estimate the power requirement during plunge
grinding of a mild steel prismatic bar (20mmx15mm)
using a grinding wheel with 3 grits/ mm2. The
diameter of the wheel is 250 mm and the wheel
rotates at 2000 rpm. The plunge feed rate is
5mm/min.
87. Surface grinding The uncut
thickness and
width vary and
the maximum
value are:
t1max and
b'max
The average
values may be
taken as one-
half of these.
λ
88. The average length of
the chip is given as:
l=(D/2) λ
But
Cos λ = (D/2 –d)/D/2
Cos λ =1-(2d/D)
d=depth of cut
λ
Cos λ can be
expanded
(keeping only
two terms
since λ is
generally
small) as
Cos λ =1- λ2 /2
Hence
λ = 2 (d/D)1/2
Substituting
this in the
value of l we
obtain
l= (dD)1/2
89. The total volume of material removed per unit time = fdB
Where: f=feed, D=depth of cut, b=width of cut in mm
The average volume per chip can be approximately taken as:
1/6 (l t1max b’ max )
The number of chips produced per unit time is: πNDBC
Taking rg = b’ max / t1max
We have
(πNDBC) x (1/6 rg l t 2
1max ) = fdB
or
t1max = [6f/πNDCrg(d/D)1/2 ] 1/2
One half of this value is to be taken as the mean uncut thickness.
90. The power consumption can be taken as:
W = (BfDUc )/60 W
Total Tangential Force
Fc = 60000 W/ π DN
Fc = 60000 BfdUc / πDN 60
Fc = 1000 BfdUc/ πDN
N= wheel RPM
The number of grit actively engaged is: CBl=CB(Dd)1/2
The average force per grit is given by:
F’c = 60000 W/ π DNCB(Dd)1/2
91. Q. Estimate the grinding force during surface grinding of a
25mm wide mild steel block with a depth of cut of 0.05
mm. The diameter of the wheel is 200 mm and the wheel
rotates at 3000 rpm. The number of grits/mm2 is measured
and found to be 3. The feed velocity of the table is
100mm/min.
104. Finishing operations
Honing operation
– The honing operation is used for finishing the inside surface
of a hole.
– The honing tool consists of a set of aluminum–oxide or
silicon- carbide bonded abrasives called stones.
– Abrasives in the form of sticks are mounted on the mandrel
which is then given reciprocating (along the hole axis)
superimposed on a uniform rotary motion.
– The grit size varies from 80 mesh to 600 mesh.
– Depending on the work material, the honing speed may vary
from 15 m/min to 60 m/min, and the honing pressure lies in
the range 1-3 N/mm2.
105. • The tolerance and finish achieved in this operation are of the
order of 0.0025mm and 0.25μm respectively.
• Honing is also done external cylindrical or flat surfaces and to
remove sharp edges on cutting tools and inserts.
• A fluid is used to remove chips and to keep temperatures.
• If not done properly, honing can produce holes that are
neither straight nor cylindrical , but with shapes that are
bellmouthed wavy or tapered.
106.
107.
108.
109. Lapping operation
• Lapping is another operation for improving the accuracy and
finish.
• It is accomplished by abrasives in the range of 120-1200 mesh.
• A lap is made of material softer than the work material.
• In this process straight, narrow groves are cut at 90 degree on
the lap surface and this surface is charged by sprinkling the
abrasive powder.
• The workpiece is then held against the lap and moved in
unrepeated paths.
• The material removal about 0.0025 mm and the lapping
pressure is generally kept in the range of 0.01-02 N/mm2
depending upon the hardness of the work material
110.
111. Polishing
• Polishing is a process that produces a smooth, lustrous surface finish.
• Two basic mechanism are involved in the polishing process.
• a) Fine-scale abrasive removal and b) softening and smearing of the surface
layers by frictional heating during polishing.
• Polishing is done with disks or belts made of fabric, leather that are coated
with fine powder of aluminum oxide or diamond.
• Buffing is similar to polishing , with the exception that very fine abrasives
are used on soft disks made of cloth.
• The abrasives are supplied externally from the stick of abrasive compound.
• Polished parts may subsequently be buffed to obtain an even finer surface
finish.
112. Electropolishing
• Mirror like finishes can be obtained on metal surface by
electropolishing, a process that that is the reverse of
electroplating.
• Because there is no mechanical contact with the workpiece,
this process is particularly suitable for polishing irregular
shapes.
• The electrolyte attacks projections and peaks on the workpiece
surface at a higher rate than the rest of the surface, producing a
smooth surface.
113. Surface treatment, coating and cleaning
Surface treatments are performed in order to:
• Improve resistance to wear, erosion, and indentation.
• Control friction
• Reduce adhesion (electrical contacts)
• Improve lubrication
• Improve resistance to corrosion and oxidation
• Improve fatigue resistance
• Rebuild surfaces on worn components
• Modify surface texture
• Impart decorative features (color)
Several techniques are used to impart these characteristics to
various types materials.
114. Mechanical surface treatment and coating
• Several techniques are used to improve the properties of
finished components.
Shot peening:
• The workpiece surface is hit repeatedly with a large large
number of cast steel glass or ceramic balls.
• This action causes plastic surface deformation, at a depth up to
1.25mm using ball size ranging from 0.125mm to 5mm in
diameter.
• Shot peening causes compressive residual stresses on the
surface, thus improving the fatigue life of the component.
• This process is used extensively on shafts, gears, springs etc.
115. Water jet peening
• A water jet of water at a pressure as high as 400MPa
impinges on the surface of the workpiece, inducing
compressive residual stresses.
• The water jet peening process has been used successfully
on steels and aluminum alloys.
Laser peening
• In laser peening the workpiece surface is subjected to laser
shocks from high powered lasers.
• This surface treatment process produces compressive
residual stress layers that are typically 1 mm.
• Laser peening has been applied successfully to jet engine
fan blades and material such as titanium and nickel alloys.
• The laser intensities necessary for this process are on the
order of 100 to 300 J/cm2
116. Roller burnishing
• Also called surface rolling, the surface of the component is cold worked
by a hard and highly polished roller or rollers.
• This process is used on various flat , cylindrical or conical surfaces.
• Roller burnishing improves surface finish by removing scratches, tool
marks and pits.
• All types of metals, soft or hard can be roller burnished.
Cladding
• In cladding , metals are bonded with a thin layer of corrosion-resistant
metal through the application of pressure, using rolls.
• Atypical application is cladding of aluminum (Alcad), in which a corrosion
–resistant layer of aluminum alloy is clad over aluminum alloy body,
usually in sheet or tubular form.
• Other applications are steel clad with stainless steel or nickel alloys.
117. Case hardening and Hard facing
Case hardening
• Case hardening processes induce residual stress on surface.
• The formation of martensite during case hardening cause s
compressive residual stress on surface.
• Such stress are desirable, because they improve the fatigue life
of components by delaying the initiation of fatigue cracks. Etc.
• Some of the case harding process are carburizing,
carbonnitriding, cyaniding, nitriding, flame hardening
Hard facing
• In hard facing, a relatively thick layer , edge or point wear
resistant hard metal is deposited on the surface using any of the
welding technique.
• Hard coting of tungsten, carbide or chromuium and
molybdenum carbide can be deposited by using electric arc.
• Hard facing alloys can be used as electrode, rod wire or powder.
• Typical application for these alloys are valve seats, oil well
drilling tools, and dies for hot metalworking.
118. Thermal spraying
• In thermal spraying processes coating (various metals
and alloys, carbides and ceramics) are applied to metal
surfaces by a spray gun with a stream of oxyfuel flame,
electric arc plasma arc.
• The coating material can be in the form of wire, rod, or
powder and the droplets or particles impact the
surface at speeds in the range of 100 to 1200 m/s.
• Typical application includes aircraft engine
components,, structures, storage tanks, and
components which require resistance to wear and
corrosion.
119. Vapor deposition
• Vapor deposition is a process in which the work
surface is subjected to chemical reaction by gases
that contain chemical compounds of the material
to be deposited.
• The coating thickness is usually a few μm.
• The deposited material can consist of metals,
alloys, carbides, nitrides, borides, ceramics, or
oxides.
• The surface may be metals, plastic, glass or paper.
• Typical application of vapor deposition are the
coating of cutting tools , drills, milling cutters,
punches, dies and wear surface.
120. Anodizing
• Anodizing is an oxidation process in which the
workpiece surface are converted to hard and porous
oxide that provides corrosion resistance and decorative
finish.
• The workpiece is an anode in an electrolytic cell
immersed in an acid bath, which results in a chemical
adsorption of oxygen from the bath.
• Organic dyes of various color can be used to produce
stable, durable surface finish.
• Typical application of for anodizing are aluminum
furniture, and utensils, architectural shapes, picture
frames, etc.
121. Diffusion coating
• Diffusion coating is a process in which an alloying
element is diffused in the surface thus altering its
properties.
• The alloying elements can be supplied in solid,
liquid, or gaseous state.
122. Electroplating, electroless plating and
electroforming
• In electroplating, the workpiece (cathode) is plated with different
metal (anode)while both are suspended in a bath containing a
water base electrolyte solution.
• All metals can be electroplated; electrolyte thickness can range
from few atomic layers to a maximum of about 0.05mm.
• Chromium, nickel, cadmium, copper, zinc, and tin are the common
plating materials.
• Electroplating is used copper plating aluminum wire, chrome
plating hardware, tin plating copper electric terminals.
• Electroless plating is done by chemical reaction and without the
use of an external source of electricity.
123. • The most common application utilizes nickel although copper is
also used.
• In electroless nickel plating, nickel chloride is reduced using
sodium hypophosphite as a reducing agent, to nickel metal, which
is then deposited on the workpiece.
• Cavities, recesses, and the inner surfaces of tubes can be plated
successfully.
• A variation of electroplating is electroforming, which actually is a
metal forming process.
• Metal is electrodeposited on a mandrel, also called mould or
matrix , which is then removed, thus coating itself becomes the
product.
• The electroforming process is particularly suitable for low
production quantities and is suitable for aerospace, electronic
applications.
124. Painting
• Because of its decorative and functional properties (such as
environmental protection, low cost, relative ease of application and the
range of available colors), paint is widely used as a surface coating.
• The engineering application of painting range from machinery to
automobile parts.
Paints are classified as:
• i) Enamels: produces a smooth coat and dry with glossy or semi glossy
appearance.
• Ii) Lacquers: which form a film by evaporation of a solvent
• iii) Water based paints: which are easily applied but have a porous
surface and absorb water, making them more difficult to clean then the
first two.
• Selection of particular paints depends on resistance to mechanical
action (abrasion, impact etc.) or to chemical actions ( acids, solvents,
detergents etc.)
• Common methods of applying paints are dipping, brushing and
spraying).
125. Cleaning Surfaces
• Cleaning involves the removal of solid, semi solid or liquid
contamination from a surface.
• Basically there are two types of cleaning processes
mechanical and chemical.
• Mechanical cleaning consists of physically disturbing the
contaminants, often with wire or fibre brushing, abrasive
blasting or steam jets.
• Many of these processes are particularly effective in
removing rust, scale and other solid contamination.
• Chemical cleaning usually involves the removal oil and
greese from the surfaces
127. 127
Accuracy of Machining process depends upon:
• The precision of mounting of
– Work
– Tool
• Their accurate movement
For repeated identical work (in mass production)
• Reduction in
– Set-up time
– Clamping time
• Minimizes production time
• Jigs and fixtures
128. 128
A jig or fixtures needs to provide the following functionality
tobeaneffectiveproductiondevice:
• Location
• Clamping
• Support
• Resistance to cutting forces
• Safety
129. Jigs and fixtures both
• Hold the work
• Support the work
• Locate the work
Jigs in addition
• Guide the cutting tool
Fixtures have
• Reference point for setting the cutting tool with
reference to the workpiece
129
130.
131. • Jigs are designed for specific operations.
• Jigs are commonly used for making parts that contains
holes.
• Jigs are used for operations like drilling, reaming,
counter boring and tapping.
• They are light in weight.
137. • Fixtures are workpiece supporting devices
• The are used for holding and locating the workpiece but
not for guiding the tool.
• The are designed on the basis of machines on which the
operations are to be performed.
• They are heavy in weight.
• Turning
• Milling
• Grinding
• Shaping
• Planning etc
Fixtures
141. 141
Functional surfaces
• It is necessary to understand the functional surfaces
present in a component and their utility from the
standpoint of its manufacture.
• The essential reason for machining is that these surfaces
are to be mating with surfaces machined in the other
part.
• It is always necessary to consider the fact that machining
increases the final cost of the component and hence
should be minimized based on the following as far as
possible:
• Location surfaces
• Support surfaces
• Clamping (holding) surfaces
142. Location surfaces
– Required to be correctly identified
– Generally identified through
• Baselines in dimensioning
• Already finished surface
142
143. 143
Support surfaces
– Surface in the end
– Not necessary to provide support for all operations
– May be provided through clamping at critical points
– Surface where maximum deflection under action
– Should not disturb the location/locators
– Should not interfere with loading/unloading
144. Clamping (holding) surfaces
– Surfaces should provide
• Easy clamping
• Shortest possible time
– Generally opposite to locating surface
– If not possible, alternate surfaces can be chosen
– Machined surfaces should be avoided
– Clamping surface area should be large
– Surfaces should have enough rigidity
100
147. • Press working has been defined as chipless
manufacturing process by which component are made
from sheet metal.
• Press working operations are caused out with help of a
metal forming machine called press which shear or
forms the component by applying force.
• The main features of the press include a stationary bed
and a powered ram can be driven towards the bed or
away from the bed to apply force or required pressure
for various metal forming operations.
• The ram is equipped with a punch or a set of punches
which have the shape of the job to be produced while
the die block is attached to the bed.
148. • Workpiece are produces or formed as the punch
descends onto the die block.
• Die – punch combination is used for the process to
impart the desired shape to the blank.
• Press tool operations of sheet metal is by far the
cheapest and fastest method to complete
manufacturing of component.
• Press working is used in large number of industries
like automobile industry, aircraft industry, lock
industry, telecommunication, electrical appliance,
utensils etc.
149.
150.
151.
152.
153. Classification of presses.
Classification on the basis of source of power.
• Manual Presses. These are either hand or foot operated
through levers, screws or gears. A common press of this
type is the arbor press used for assembly operations.
• Mechanical presses. These presses utilize flywheel
energy which is transferred to the work piece by gears,
cranks, eccentrics, or levers.
• Hydraulic Presses. These presses provide working force
through the application of fluid pressure on a piston by
means of pumps, valves, intensifiers, and accumulators.
• Pneumatic Presses. These presses utilize air cylinders to
exert the required force. These are generally smaller in
size and capacity than hydraulic or mechanical presses,
and therefore find use for light duty operations only.
156. Classification on the basis of number of slides
• Single Action Presses. A single action press has one
reciprocation slide that carries the tool for the metal
forming operation. It is the most widely used press for
operations like blanking, coining, embossing, and drawing.
• Double Action Presses. A double action press has two
slides moving in the same direction against a fixed bed. It
is more suitable for drawing operations, especially deep
drawing, than single action press.
• Triple Action Presses. A triple action press has three
moving slides. Two slides move in the same direction as in
a double – action press and the third or lower slide moves
upward through the fixed bed in a direction opposite to
that of the other two slides. This action allows reverse –
drawing, forming or bending operations against the inner
slide while both upper actions are dwelling.
157. Classification on the basis
of frame and construction
• Arch – Frame Presses.
These presses have their
frame in the shape of an
arch. These are not
common.
• Gap Frame Presses. These
presses have a C-shaped
frame. These are most
versatile and common in
use, as they provide un
obstructed access to the
dies from three sides and
their backs are usually open
for the ejection of
stampings and / or scrap.
158. Straight Side Presses. These
presses are stronger since the
heavy loads can be taken in a
vertical direction by the massive
side frame and there is little
tendency for the punch and die
alignment to be affected by the
strain.
Horn Presses. These presses
generally have a heavy shaft
projecting from the machine frame
instead of the usual bed. This press
is used mainly on cylindrical parts
involving punching, riveting,
embossing, and flanging edges.
159. Classification of dies
There is a broader classification of single operation dies and multi-
operation dies.
• (a) Single operation dies are designed to perform only a single
operation in each stroke of ram.
• (b) Multi operation dies are designed to perform more than one
operation in each stroke of ram.
Single operation dies are further classified as described below.
Cutting Dies
• These dies are meant to cut sheet metal into blanks. The
operation performed so is named as blanking operation.
160. Forming Dies
• These dies are used to change two shape of workpiece material by
deforming action. No cutting takes place in these dies.
Compound Dies
• In these dies two or more cutting actions (operations) can be
executed in a single stroke of the ram.
Combination Dies
• These dies are meant to do combination of two or more
operations simultaneously. This may be cutting action followed by
forming operation. All the operations are done in a single action of
ram.
161. Progressing Dies
• These dies are able to do progressive actions (operations) on the
workpiece like one operation followed by another operation and
so on. An operation is performed at one point and then workpiece
is shifted to another working point in each stroke of ram.
162. Press operations: Shearing
• Shearing is a cutting operation used to remove a blank of required
dimensions from a large sheet.
• A metal being sheared between a punch and a die.
163. • Shearing begins with formation of cracks on both sides of the
blank, which propagates with application of shear force.
• The fracture progresses downwards with the movement of upper
shear and finally results in separation from parent strip.
• Shearing a blank involves plastic deformation due to shear stress.
Therefore, the force required for shearing is theoretically equal to
the shear strength of blank material.
165. Punching/Blanking
Punching or blanking is a process in
which the punch removes a
portion of material from the larger
piece or a strip of sheet metal.
If the small removed piece is
discarded, the operation is called
punching, whereas if the small
removed piece is the useful part
and the rest is scrap, the operation
is called blanking.
166. Notching
• Punching the edge of a sheet,
forming a notch in the shape of
a portion of the punch.
• It usually removes a small
portion from edge or side of a
sheet.
167. Piercing
The typical operation,
in which a cylindrical
punch pierces a hole
into the sheet.
Sometimes called
Punching.
Identical to Blanking,
only the punched out
portion which is coming
out through die is
scrap.
Normally Blanking
follows a piercing
operation
168.
169.
170. • Trimming:
When parts are produced by die casting or drop forging, a
small amount of extra metal gets spread out at the parting
plane. This extra metal, called flash, is cut – off before the
part is used, by an operation called trimming.
• Shaving:
Shaving operation is a finishing operation where a small
amount of metal is sheared away from an already blanked
part. Its main purpose is to obtain better dimensional
accuracy.
173. Drawing
It is a cold drawing operation.
A process of making utensils, pressure
vessels, gas cylinders, cans, shells,
kitchen sinks, etc from blanks.
Similar to blanking except that the
punch and die are provided with the
necessary rounding at the corners to
allow smooth flow of metal during
drawing & to avoid shearing.
One of the widely used sheet metal
forming operations.
Cupping and Deep Drawing are two
operations.
Press operations: Forming
174.
175.
176.
177.
178. • Proper selection of a press is necessary for successful and
economical operation.
• Press is a costly machine, and the return on investment depends
upon how well it performs the job.
• There is no press that can provide maximum productively and
economy for all application.
• Hence when a press is required to be used for varying jobs,
compromise is generally made between economy and
productivity.
Important factors affecting the selection of a press are:
Size
• Bed and slide areas of the press should be of enough size so as to
accommodate the dies to be used.
• Stroke requirements are related to the height of the parts to be
produced.
179. Force and Energy
• Press selected should have the capacity to provide
the force and energy necessary for carrying out the
operation.
Press Speed
• Fast speeds are generally desirable, but they are
limited by the operations performed.
• Size, shape and material of workpiece, die life,
maintenance costs, and other factors should be
considered while attempting to achieve the highest
production rate at the lowest cost per piece.
181. Press selection
• Required force f for: blanking, piercing,
lancing, etc., is given by
» h = gage thickness, m
» ls = length to be sheared, m
» U= ultimate tensile strength 181
182. Press selection
Example:
Circular disks 50 cm in diameter are to be blanked from No. 6 gage commercial-
quality, low-carbon steel.
– thickness of 6 gage steel = 5.08 x 10-3 m
– ultimate tensile strength, U = 330 x103 kN/m2
required blanking force
f = 0.5 x (330 x 103) x (5.08 x 10-3) x (π x 50 x 10-2) = 1316.6kN
Table 9.3: 1750kN press
182
183. The clearance between the die and punch can be determined as
c = 0.003 t. p
where
t is the sheet thickness
p is the shear strength of sheet material
For blanking operation, die size = blank size, and the punch is made
smaller, by considering the clearance.
The maximum force, F required to be exerted by the punch to shear
out a blank from the sheet can be estimated as
F = t. L. p
where
t is the sheet thickness,
L is the total length sheared
p is the shear strength of the sheet material.
184. • Stripping force.
Two actions take place in the punching process–
punching and stripping. Stripping means extracting the
punch. A stripping force develops due to the spring
back of the punched material that grips the punch. This
force is generally expressed as a percentage of the force
required to punch the hole, although it varies with the
type of material being punched and the amount of
clearance between the cutting edges. The following
simple empirical relation can be used to find this force.
SF = 0.02 L.t
where
SF = stripping force, kN
L = length of cut, mm
t = thickness of material, mm
185.
186. Example: A circular blank of 30 mm diameter is to be cut from 2 mm
thick 0.1 C steel sheet. Determine the die and punch sizes. Also
estimate the punch force and the stripping force needed. You may
assume the following for the steel : Tensile strength: 410 MPa ; shear
strength : 310 MPa
Solution:- For cutting a blank, die size = blank size = 30mm
Clearance = c = 0.003 t. p = 0.003 x t x p = 0.003 x 2 x 310 = 1.86 mm
Punch size = blank size – 2 clearance
= 30 – 2 x 1.86 = 26.28 mm
Punch force needed = L. t. p = π x 30 x 2 x 310 (L= πD)
= 58.5 kN
Stripping force needed = 0.02 L. t
= 0.02 x p x 30 x 2
= 3.77 kN
187.
188. Important consideration for design of a die set
The following important points should be considered while designing
a die set:
• Cost of manufacturing depends on the life of die set, so
selection of material should be done carefully keeping
strength and wear resistant properties in mind.
• Die is normally hardened by heat treatment so design
should accommodate all precautions and allowances to
overcome the ill effects of heat treatment.
• Accuracy of production done by a die set directly
depends on the accuracy of die set components.
• Standardized components should be used as much as
possible.
• Easy maintenance should be considered. Replacement
of parts should be easy.