This document provides an overview of material removal processes, also known as subtractive manufacturing. It discusses turning, milling, and drilling operations as the three principal machining processes. It also covers cutting tool materials, cutting fluids, and machining processes for producing various shapes such as round, cylindrical, and irregular shapes. The document discusses factors like environmental safety, accuracy, cost effectiveness, and advantages and disadvantages of machining processes.

1. 2ND MINOR ASSIGNMENT
MATERIAL REMOVAL PROCESS
SUBMITTED TO :
SUBMITTED BY:
MR. ADITYA MISHRA SIR SAIF ALI
SIDDIQUI
k-10672(CE)
6TH SEM.

2. • Introduction
• Definition
• Principle
• Procedure / working
• Environmental safety
• Accuracy
• Industrial application
• The price
• Advantages and disadvantages
• Availabilty of skill labour
• Future scope
• Conclusion
• References

3. • Material removal process is any of various processes in
which a piece of raw material is cut into a desired final
shape and size by a controlled material-removal process.
The processes that have this common theme, controlled
material removal, are today collectively known as
subtractive manufacturing, in distinction from processes of
controlled material addition, which are known as additive
manufacturing. Exactly what the "controlled" part of the
definition implies can vary, but it almost always implies the
use of machine tools (in addition to just power tools and
hand tools).

4. • Material removal process is a part of the manufacture of
many metal products, but it can also be used on
materials such as wood, plastic, ceramic, and
composites.[1] A person who specializes in machining is
called a machinist. A room, building, or company where
machining is done is called a machine shop. Machining
can be a business, a hobby, or both.
• Much of modern day machining is carried out by
computer numerical control (CNC), in which computers
are used to control the movement and operation of the
mills, lathes, and other cutting machines.

5. • The three principal machining processes are classified as
turning, drilling and milling. Other operations falling into
miscellaneous categories include shaping, planing, boring,
broaching and sawing.
• Turning operations are operations that rotate the workpiece
as the primary method of moving metal against the cutting
tool. Lathes are the principal machine tool used in turning.
• Milling operations are operations in which the cutting tool
rotates to bring cutting edges to bear against the workpiece.
Milling machines are the principal machine tool used in
milling.

6. • Drilling operations are operations in which holes are
produced or refined by bringing a rotating cutter with cutting
edges at the lower extremity into contact with the work
piece. Drilling operations are done primarily in drill presses
but sometimes on lathes or mills.
• Miscellaneous operations are operations that strictly
speaking may not be machining operations in that they may
not be swarf producing operations but these operations are
performed at a typical machine tool. Burnishing is an
example of a miscellaneous operation. Burnishing produces
no swarf but can be performed at a lathe, mill, or drill press.

7. • Fundamental Of Cutting
• Cutting processes are among the most important of
manufacturing operation. They are often necessary in order to
impart the desired surface finish and dimensional accuracy to
component, particularly those with complex shape that cannot be
produced economically or properly by other techniques.
• A large number of variables have significant influence on the
mechanics of chip formation in cutting operations. Commonly
observed chip types are continuous, built-up edge, discontinuous
and segmented. Among important process variables are tool
shape and material, cutting conditions such as speed, feed, and
depth of cut, use of cutting fluids, and the characteristics of the
machine tool, workholding device, fixturing, as well as the
characteristics of the workpiece material, parameters influenced
by these variables are force and power consumption, tool wear,
surface finish and integrity, temperature, and dimensional
accuracy of the workpiece. Machinability of materials depends not

8. • Cutting-Tool Materials and Cutting Fluids
• A variety of cutting-tool materials have been developed over the past
century for specific applications in machining operation. These material
have a wide range of mechanical and physical properties, such as hot
hardness, toughness, chemical stability and resistance to chipping and
wear. Various coating have been developed, resulting in major
improvement in tool life. The selection of appropriate tool material not
only on the material to be machined, but also on process parameters and
the characteristics of the machine tools.
• Cutting fluid are an important factor in machining operations.
Generally, slower operations with high tool pressures require a fluid with
good lubricating characteristics. In high-speed operations with significant
temperature rise, fluids with cooling capacity are preferred. Selection
should be include consideration of various adverse effects of cutting
fluids on products, machinery, personnel, and the environment.

9. • Machining Processes for Producing Round Shape.
• Cutting processes that produce external and internal circular profile
are turning, boring and drilling. Reaming, tapping and die threading are
processes for finishing workpieces. Chip formation in all these processes
is essentially the same. However, because of the three-dimensional
nature of the cut, chip movement and its control are important
considerations since otherwise they interfere with the cutting operation.
Chip removal can be significant problem especially in drilling and tapping
and can be lead to tool breakage. Each process should be studied in
order to understand the interrelationships of design parameters, such as
dimensional accuracy, surface finish and integrity, and process
parameters such as speed, feed, depth of cut, tool material and shape,
and cutting fluids.
• Design guidelines should be followed carefully to take full advantage of
the capabilities of each process. Part to be machined may have been
produced by casting forging, extrusion, powder metallurgy, and so on.
The closer to the blank to be machined to the final shape desired, the
fewer the number and extent of machining processes required. Such net-
shape manufacturing is of major significance in minimizing costs.

10. • Machining Processes for Producing Various Shapes.
• Some of the most versatile machining processes are milling,
planing, shaping, broaching and sawing. Milling is the one of
the most useful processes because of its capability to produce
a variety of shapes from workpieces. Although there are
similarities with processes such as turning, drilling, and boring,
most of these processes utilize multitooth tools and cutters at
various axes with respect to the workpieces. The machine
tools employed have various features, attachments and
considerable flexibility in operation.
• Gear manufacturing by various forming and shaping
processes. It also produced by machining, either by form
cutting or generating, with the latter producing gears with
better surface finish and greater dimensional accuracy. The
surface finish and accuracy of tooth profile are further
improved by gear finishing processes such as shaving,
burnishing and grinding.

11. • Abrasive Machining and Finishing Operations
• Grinding and various abrasive-removal processes are capable
of producing the finest accuracy and surface finish in
manufactured products. The majority of abrasive processes are
basically finishing operations that are usually performed on
machined or cold-worked parts. However, abrasives are also used
for large-scale material-removal processes, such as creep-feed
grinding and snagging in foundries.
• A variety of abrasive processes and machinery are available for
surface, external, and internal grinding. The selection of abrasives
and process variable in these operations must be controlled in
order to obtain the desired surface and dimensional accuracy.
Otherwise, damage to surfaces such as burning, heat checking,
and harmful residual stresses may develop. Several finishing
operations are available for debarring. Because contribute
significantly to product cost, proper selection and implementation
of finishing operations are important.

12. Environmental safety ensures that the machining
processes and their byproducts do not pose hazards to the
environment. In addition to any state and local
environmental regulations, manufacturers must comply with
the laws and regulations of the U.S. Environmental
Protection Agency.

13. The third desirable characteristic of machining processes is
accuracy. Accuracy refers to the ability of the machining
processes to consistently yield an item that accurately
meets specifications on the first cut.

14. The last desirable characteristic of machining processes is cost-
effectiveness. To be cost-effective, the machining processes
need to be performed at a cost that yields a profit for the
manufacturer but is still affordable for customers.
The cost-effectiveness of machining processes is mainly affected
by the following factors:
The price of materials
The price and reliability of equipment
The availability of skilled labor
The cost of compensation for employees
The cost of overhead (rent, insurance, utilities)
The speed of the machining processes
The manufacturer's competitive position in the marketplace

15. • Why Machining is Important
• Variety of work materials can be machined
• Most frequently used to cut metals
• Variety of part shapes and special geometric features
• possible, such as:
• – Screw threads
• – Accurate round holes
• – Very straight edges and surfaces
• Good dimensional accuracy and surface finish_x0000_

16. Manufacturers will of course attempt to negotiate the best
prices for the purchase or rental of their equipment.
However, the reliability of the equipment — how long it can
operate perfectly without the need for repair or replacement
— affects both the true cost of the equipment and the
speed of machining processes.

17. Wasteful of material
– Chips generated in machining are wasted material, at
least in the unit
operation
• Time consuming
– A machining operation generally takes more time to
shape a given part
than alternative shaping processes, such as casting,
powder metallurgy, or forming_x0000_

18. Access to a skilled labor pool is crucial for manufacturers.
Skilled labor includes the employees who operate the
machines and the employees who supervise them and the
plants

19. • The mathematical model can be developed different work
piece and electrode materials for EDM and WEDM
process.
• Responses like roundness circularity ,cylindricity,
machining cost etc. are to be considered in the further
research .
• The standard optimization procedure can be developed
and the optimal results are to be validated.

20. • Various processes in which a piece of raw material is cut
into a desired final shape and size by a controlled
material-removal process. The processes that have this
common theme, controlled material removal, are today
collectively known as subtractive manufacturing, in
distinction from processes of controlled material addition,
which are known as additive manufacturing.

21. •
• [1]. C.M. Cheah e tal. - “Rapid Sheet Metal Manufacturing,
• Part 2: Direct Rapid Tooling”, International Journal
• of Advanced Manufacturing Technology, 19 (2002), pp. 510–515.
•
• [2]. B. Engel, D.L. Bourell - “Titanium Alloy Powder
• Preparation for Selective Laser Sintering”, Rapid Prototyping
• Journal, 6(2)/2000, pp. 97–106.
• [3]. D.L. Bourell et al. - “Selective Laser Sintering of
• Metals and Ceramics”, International Journal of Powder
• Metall., 28(4)/1992, pp. 369–381.
•
• [4]. R. M. German – „Powder Metallurgy of Iron and
• Steel”, New York, Wiley, 1998.
•
• [5]. A. Gregorian s.a. – „Accuracy Improvement in Rapid
• Prototyping Machine”, Solid Freeform Fabrication