Welding and its types Powerpoint

1. Welding, types of welding, types of weld joints, types of
welds, features of weld joints,
Arc welding,SMAW,GMAW,GTAW,Resistance welding, Spot
& seam welding,oxyfuel Gas welding, Weld
Quality,Defects,inspection & testing of
welds,Brazing,Soldering,Sheet metal working, cutting
operation, bending operation,presses,roll bending &
forming, Mechanical Assembly, Threaded
fasteners,Washers,rivets,eyelets,press fittings, shrink &
expansion fit, Snap fits,Retatiniing rings, Cotter pins,
Shaping processes for plastics,extrusion,Injection Molding,
compression molding, Blow molding,thermofrming.
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2. Recommended Books
 Manufacturing Engineering & Technology BY:
Kalpakjain,shmid
 Process & Materials of Manufacture BY: Lindberg
 Materials & Processes in Manufacturing BY:Degarmo
 Fundamentals of Modern Manufacturing,
Materials, Processes & Systems BY: Groover
 Manufacturing Processes & Systems BY: Phillip F.
Ostwald
 Design & Technology BY: James Garratt
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3. Definitions
 Engineering: The application of scientific and
mathematical principles to practical ends such as the
design, manufacture, and operation of efficient and
economical structures, machines, processes, and systems.
 Technology: The application of science to provide society
and its members with those things that are needed or
desired.
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4. Manufacturing - Economically Important
Manufacturing is
one way by which
nations create
material wealth.
U.S. economy:
Sector
% of
GNP
Manufacturing 20%
Agriculture, minerals, etc. 5%
Construction & utilities 5%
Service sector – retail,
transportation, banking,
communication, education, and
government
70%

5. Definitions
 Manufactuirng: Latin words, manus (hand) and factus
(make);the combination means made by hand.
 Systems of manufacturing: refer to the ways of
organizing people and equipment so that production can
be performed more efficiently
 Division of labor: Tasks and Subtasks for large scale
production (Wealth of Nations)
 Industrial Revolution (circa 1760–1830) defined the
future of nations from onwards, (1)massproduction,(2)
scientific management movement,(3)assembly lines,
and(4) electrification of factories.
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6. Manufacturing - Technologically
 Manufacturing is the application of physical and
chemical processes to alter the geometry, properties,
and/or appearance of a given starting material to make
parts or products; manufacturing also includes assembly
of multiple parts to make products.
 Manufacturing also includes assembly
 Almost always carried out as a sequence of operations
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7. Manufacturing - Economically
Manufacturing
as an economic
process
Transformation of materials into items of greater value
by means of one or more processing and/or assembly
operations
 Manufacturing adds value to the material by changing
its shape or properties, or by combining it with other
materials
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8. Classification of Industries
1. Primary industries – cultivate and exploit natural
resources
 Examples: agriculture, mining
2. Secondary industries – convert output of primary
industries into products
 Examples: manufacturing, power generation,
construction
3. Tertiary industries – service sector
 Examples: banking, education, government, legal
services, retail trade, transportation
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9. Classification of Industries
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10. Types of Manufactured Products
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• Consumer goods are products purchased directly by
consumers, such as cars, personal computers etc
• Capital goods are those purchased by companies to produce
goods and/or provide services.

11. The word production is interchangeably with the word
manufacturing but some time continuous production cannot be
termed as manufacturing.
Manufactured Products:
Discrete Products: individual parts, such as nails, gears, bearing balls,
cans, engine blocks, …
Continuous Products: items produced by continuous processes, such as
sheet metal coil (almost), pipes, spool of wire…….
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Product
Design
Materials
Selection Manufacturing Marketing
Production vs Manufacturing

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 Discrete Products: individual parts, such as
nails, gears, bearing balls, cans, engine
blocks, …
 Low production: 1 to 100/yr
 Medium production: 100 to 10,000/yr
 High/mass production: over 10,000 units/yr
 Continuous Products: items produced by
continuous processes, such as sheet metal
coil (almost), oil refinery, …
Manufacturing Products

13. Production Quantity Q
 The quantity of products Q made by a factory has an
important influence on the way its people, facilities, and
procedures are organized
 Annual production quantities can be classified into
three ranges:
 Production range Annual Quantity Q
 Low production 1 to 100 units
 Medium production 100 to 10,000 units
 High production 10,000 to millions of units
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14. Product Variety P
 Product variety P refers to different product types or
models produced in the plant
 Different products have different features
 They are intended for different markets
 Some have more parts than others
 The number of different product types made each year
in a factory can be counted
 When the number of product types made in the factory
is high, this indicates high product variety
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15. P versus Q in Factory Operations
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16. Manufacturing Capability
 A Manufacturing system has
 Processes (machines, equipment and tools) and systems
 People (Human resource)
 Materials
 Manufacturing capability is the limitations :
1. Technological processing capability
2. Physical product limitations
3. Production capacity
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17. Technological Processing Capability
 The Processes are specific to the material being
processed and added value into.
 Technical skill set
 Software Skills
 Examples:
 A machine shop cannot roll steel
 A steel mill cannot build cars
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18. Physical Production Limits
 A manufacturing setup is limited in terms of the size and
weight of the products that can be accommodated
 Heavier products need specialized cranes to move
them between work stations
 Machine size limits the part size
 Material Handling systems limit the product size
 Examples:
 A car manufacturer cannot manufacture ships
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19. Production Capacity Capability
 Plant Capacity, or Production Capacity, defined as the
maximum rate of production (through put) that a
plant can achieve under assumed operating conditions.
 Through put is normally measured in terms of unit
products / unit time
 The through put is generally limited by bottleneck
machine
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20. Materials in Manufacturing
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21. Metals
Metals in industry are generally alloys can be divided in
to two groups:
Ferrous:-those which contain iron.
Nonferrous: those which contain no iron.
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Two basic groups:
1. Ferrous metals - based on iron, comprises about
75% of metal tonnage in the world:
 Steel = Fe- C alloy (0.02 to 2.11% C)
 Cast iron = Fe-C alloy (2% to 4% C)
2. Nonferrous metals - all other metallic elements and
their alloys: aluminum, copper, magnesium, nickel,
silver, tin, titanium, etc.

22. CERAMICS
 A ceramic material is an inorganic compound
consisting of a metal or semimetal + one or more
non metals.
 Typical nonmetallic elements are oxygen, nitrogen,
and carbon.
 The general properties from these bonding results are:
high hardness & stiffness, brittleness, electrically &
thermally insulated & chemically inert.
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23. EXAMPLES
 Important examples are silica, alumina, hydrous
aluminum silicate (Kaolinite),clay, carbides,
Nitrides.
 Clay (make tiles & pottery)
 Silica (basis of all glass materials)
 Carbide (used as cutting tool materials)
 Nitrides (cutting tools & grinding abrasives)
 Refractory ceramics (which are capable of high
temperature) furnace wall, crucibles & molds.
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24. Ceramics
For processing, ceramics divide into:
1. Crystalline ceramics – includes:
 Traditional ceramics, such as clay (hydrous
aluminum silicates)
 Modern ceramics, such as alumina (Al2O3)
2. Amorphous ceramics: Glasses – mostly based on
silica (SiO2).
Example: silica exits in crystalline quartz. When this
mineral is melted & cooled it solidifies to form fused
silica, which has a noncrystalline structure.
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25. Polymers
 Poly refers to multiple element Compound formed of
repeating structural units called mers, whose
atoms share electrons to form very large molecules by
covalent bonding.
 Elements in polymers are usually carbon plus other
elements like H,O,N& Cl.
 Polymers have a glassy, mixture of glassy & crystalline.
 Properties: low density, high electrical resistivity
& low thermal conductivity.
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26. Polymer categories
 Three categories:
1. Thermoplastic polymers - can be subjected to
multiple heating and cooling cycles without
altering molecular structure.e.g polyetylene,PVC &
nylon.
2. Thermosetting polymers - molecules chemically
transform (cure) into a rigid structure – cannot be
reheated.e.g phenolics,amino resins & epoxies.
3. Elastomers - shows significant elastic behavior
e.g. natural rubber,neoprene,silicone &
polyurethane.
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27. Composites
 Material consisting of two or more phases that are
processed separately and then bonded together
to achieve properties superior to its constituents
 Phase - homogeneous mass of material, such as
grains of identical unit cell structure in a solid
metal.
 Usual structure consists of particles or fibers of one
phase mixed in a second phase ,called matrix.
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28. In Addition: Composites
Venn diagram of
three basic material
types plus composites
Nonhomogeneous mixtures of the other three basic
types rather than a unique category
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29.  In nature wood, synthetically we can produce
composites of greater value.epoxy-kevlar composite.
 Properties depend on components, physical shapes of
components, and the way they are combined to form
the final material .
 Aerospace industry is one of the biggest user of
composites, car bodies, Boat hulls, tennis racket &
carbide tools.
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Composites

30. Properties of composites
 Strength to weight ratio & stiffness to weight ratio.
 Fatigue properties & toughness
 Corrosion does not occur
 Better appearance and control of surface smoothness.
Disadvantages:
 Anisotropic( properties changes with direction)
 Attack of chemicals or solvents
 Manufacturing methods are costly.
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31. Manufacturing Processes
Manufacturing process is a designed procedure that
results in physical and/or chemical changes to a starting
work material with the intention of increasing the value of
that material.
Two basic types:
1. Processing operations - transform a work material
from one state of completion to a more advanced
state. Operations that change the geometry,
properties, or appearance of the starting material
2. Assembly operations - join two or more components
to create a new entity
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32. Classification of Manufacturing Processes
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33. Shaping Processes –Categories
1. Solidification processes - starting material is a
heated liquid or semi fluid
2. Particulate processing - starting material
consists of powders
3. Deformation processes - starting material is a
ductile solid (commonly metal)
4. Material removal processes - starting material is
a ductile or brittle solid
5. Casting ,forging and machining processes are
included in shaping processes.
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34. Solidification Processes
Starting material is heated sufficiently to transform
it into a liquid or highly plastic state
Examples: metal casting, plastic molding
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35. Particulate Processing
 Starting materials are powders of metals or ceramics
 Usually involves pressing and sintering(powder into
solid) in which powders are first compressed and then
heated to bond the individual particles
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36. Deform/Shape Material
1. Casting
2. Rolling/Forging
3. Extrusion/Drawing
4. Sheet metal forming
5. Powder metal processes
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37. Deformation Processes
 Starting work part generally heated is shaped by
application of forces that exceed the yield
strength( turning point elastic to plastic region)of the
material
 Examples: (a) forging, (b) extrusion
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38. Material Removal Processes
 Excess material removed from the starting piece so
what remains is the desired geometry
 Examples: machining such as turning, drilling, and
milling; also grinding and nontraditional processes
(laser, electron beam, electric discharge etc)
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39. Property Enhancing Processes
 Performed to improve mechanical or physical
properties of work material
 Part shape is not altered, except unintentionally
 Examples:
 Heat treatment of metals and glasses for case hardening
 Heat treatment of metals for strain relieving
 Redox painting for corrosion resistance
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40. Surface Processing Operations
 Cleaning - chemical and mechanical processes to
remove dirt, oil, and other contaminants from the
surface
 Surface treatments - mechanical working such as
sand blasting, and physical processes like diffusion
& ion implementation.
 Coating and thin film deposition - coating
exterior surface of the work part.
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41. Sand Blasting
 Sandblasting or bead blasting is a term for the process
of smoothing, shaping and cleaning a hard surface by
forcing solid particles across that surface at high
speeds; the effect is similar to that of using sandpaper,
but provides a more even finish with no problems at
corners.
 Sandblasting is a general term used to describe the act
of propelling very fine bits of material at high-velocity
to clean or etch a surface. Sand used to be the most
commonly used material.
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Sandblasting is used to clean surfaces, remove rust, oxidation, or
finishes, preparing surfaces for new coating applications. It is highly
effective for large equipment, surface preparing and paint/rust
removal.

43. Assembly Operations
 Two or more separate parts are joined to form a
new entity
 Types of assembly operations:
1. Joining processes – create a permanent joint
 Welding, brazing, soldering, and adhesive
bonding
2. Mechanical Fastening – fastening by mechanical
methods
 Threaded fasteners (screws, bolts and nuts);
press fitting, expansion fits
 Permanent fastening method
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44. Join Two or More Materials
1. Welding
2. Brazing
3. Soldering
4. Adhesive bonding
5. Fastening (rivets, nuts, bolts)
6. Press fitting
7. Vacuum Assembly
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45. Production Machines and Tools
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Examples of a few process tooling

46. Production Systems
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Two Categories
• Production facilities refer to the physical equipment
and the arrangement of equipment in the factory.
• Manufacturing support systems are the procedures
and software used by the company to manage
production and solve the technical and logistics
problems encountered in ordering materials, moving
work through the factory, and ensuring that products
meet quality standards.

47. Production Systems
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Low-Quantity Production
• (1–100 units/year),
• Job shop type arrangement (fixed position layout)

48. Production Systems
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Medium-Quantity Production
• (100–10000 units/year),
• Batch Production (process layout, cellular layout)
cellular layout
process layout

49. Production Systems
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Medium-Quantity Production
• (10000–millions units/year),
• Dedicated Production Lines, mass production (product
layout)

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Manufacturing Support Systems
• The manufacturing engineering department is
responsible for planning the manufacturing processes,
tooling and materials
• Production Planning and Control is responsible for
logistics problem in manufacturing, ordering
materials and purchased parts, scheduling
production
• Quality control Producing high-quality products,
customer focused

51. Manufacturing Support Systems
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52. Modern Trends in Manufacturing
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(1) Lean production and Six Sigma
(2) Globalization
(3) Environmentally conscious manufacturing,
(4) Microfabrication and nanotechnology

53. Lean Production System
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Essentially TOYOTA PRODUCTION SYSTEM
Minimize Resources And Improve Quality (“WASTE”)
(1) Production of defective parts,
(2) Production of more parts than required,
(3) Excessive inventories,
(4) Unnecessary processing steps,
(5) Unnecessary movement of workers,
(6) Unnecessary movement and handling of materials,
(7) Workers waiting.

54. Six Sigma
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1980s at Motorola Corporation in the United States.
1990s at General Electric in the United States.
‘‘A quality-focused program that utilizes worker teams
to accomplish projects aimed at improving an
organization’s operational performance.’’
Improvement of Process Capability through
variance reduction by using DMAIC technique and
a standard deviation (Sigma) based performance
metering mechanism.

55. GLOBALIZATION AND OUTSOURCING
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China, India, Brazil, Indonesia and Mexico have
developed their manufacturing infrastructures and
have very cheap labor
Globalization Outsourcing
Outsourcing types
Off shore outsourcing distant countries
Near Shore Outsourcing regional countries

56. GLOBALIZATION AND OUTSOURCING
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China, India, Brazil, Indonesia and Mexico have
developed their manufacturing infrastructures and
have very cheap labor
Globalization Outsourcing
Outsourcing types
Off shore outsourcing distant countries
Near Shore Outsourcing regional countries

57. ENVIRONMENTALLY CONSCIOUS
MANUFACTURING
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Green manufacturing, Cleaner production, and Sustainable
Manufacturing
(1) Materials that require minimum energy to produce,
(2) Processes that minimize waste of materials and
energy,
(3) Design to be recycled or reused,
(4) Design to disassembled
(5) Minimize the use of hazardous and toxic materials,
(6) Recyclability at end of its useful life.

58. MICROFABRICATION AND
NANOTECHNOLOGY
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Microfabrication features sizes are in the micrometer
range 1 µm = 10-3 mm = 10-6 m.
Examples include ink-jet printing heads, compact discs
(CDs and DVDs), and microsensors
Nano fabrication features sizes are in the nanometer
range 1 nm = 10-6 mm = 10-9 m.
Eamples Ultra-thin coatings for catalytic converters, flat
screen TV monitors, and cancer drugs are examples of
products based on nanotechnology

59. Any Question
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