MACHINING EQUIPMENT
‫معدات تشغيل‬
PRE 314
Production Department
3rd Year
Dr. Shokria Abbas Ahmed
MACHINING EQUIPMENT
Traditional Processes
Dr. Aly Elmasry
Non-Traditional Processes
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Mechanical Energy Processes
Electrochemical Machining
Processes
Thermal Energy Processes
Chemical Machining
Dr. Shokria Abbas Ahmed
DIFINATION OF NONTRADITIONAL
PROCESSES
A group of processes that remove excess
material by various techniques involving
mechanical, thermal, electrical, or chemical
energy (or combinations of these energies) but
do not use a sharp cutting tools as it needs to
be used for traditional manufacturing processes.
Why Nontraditional Processes are Important?
Need to machine new materials having high strength
and hardness, such as nimonic alloys and alloys with
alloying elements such as tungsten, molybdenum, and
columbium are difficult to machine by the traditional
methods.
 Need for unusual and/or complex part (Fig.1)
geometries that cannot easily be accomplished by
conventional machining.
 A very high accuracy is desired besides the complexity
of the surface to be machined.
 Need to avoid surface damage that often accompanies
conventional machining.

Machining of Complex Shaped Workpieces
Fig.1
Classification of Nontraditional
Processes by Type of Energy Used
Mechanical - erosion of work material by a high velocity
stream of abrasives or fluid (or both) is the typical form
of mechanical action
 Electrochemical energy to remove material (reverse of
electroplating)
 Thermal – thermal energy usually applied to small
portion of work surface, causing that portion to be
removed by fusion and/or vaporization
 Chemical – chemical etchants selectively remove
material from portions of workpart, while other
portions are protected by a mask

CLASSIFICATION OF NONTRADITIONAL
MACHINING
Non-traditional Machining Methods are classified according to the
major energy sources employed in machining.
I. Mechanical Energy Processes
⎯ Abrasive Jet Machining (AJM)
⎯ Ultrasonic Machining (USM)
⎯ Water Jet Machining (WJM)
⎯ Abrasive Water Jet Machining (AWJM)
II. Electrochemical Energy Processes
⎯ Electrochemical Machining (ECM)
⎯ Electrochemical Grinding (ECG)
⎯ Electrochemical Deburring (ECD)
III. Thermal Energy Processes
⎯ Electro-discharge machining (EDM)
⎯ Laser Beam Machining (LBM)
⎯ Electron Beam Machining (EBM)
IV. Chemical Energy Processes
⎯ Chemical Milling (CHM)
⎯ Photochemical Milling (PCM)
CLASSIFICATION OF
NONTRADITIONAL MACHINING
Characteristics of Non Traditional Machining
(NTM) Processes

Material removal may occur with chip formation or even no chip
formation may take place. For example in AJM, chips are of microscopic
size and in case of Electrochemical machining material removal occurs due
to electrochemical dissolution at atomic level.

No lay pattern on work surface, no direct physical contact between the
tool and the workpiece .

In NTM, there may not be a physical tool present. For example in laser jet
machining, machining is carried out by laser beam. However in
Electrochemical Machining there is a physical tool that is very much
required for machining.
In NTM, the tool need not be harder than the work piece material. For
example, in EDM, copper is used as the tool material to machine hardened
steels.
 Tool forces do not increase as the work material gets harder.


Economic metal removal rate does not decrease as the work material gets
harder.

Performance depends on thermal, electrical and chemical properties of
workpiece materials.

Uses different kinds of energy in direct form.
SELECTION OF PROCESS:
The correct selection of the non-traditional
machining methods must be based on the
following aspects.
I. Physical parameters of the process
II. Shape to be machined
III. Process capability
IV. Economics of the processes
I. PHYSICAL PARAMETER OF THE PROCESS
The physical parameters of the different NTM are given in
the Table 1.0 which indicates that PAM and ECM require
high power for fast machining. EBM and LBM require high
voltages and require careful handling of equipment. EDM
and USM require medium power. EBM can be used in
vacuum and PAM uses oxygen and hydrogen gas.
Table 1
II. Shapes Cutting Capability
The various NTM have some special shape cutting
capability as given below:
➢ Micro-machining and drilling: LBM and EBM
➢ Cavity sinking and standard hole Drilling: EDM
and USM
➢ Fine hole drilling and contour machining: ECM
➢ Clean, rapid cuts and profiles: PAM
➢ Shallow pocketing: AJM
III. Process capability
EDM which achieves higher accuracy has the lowest
specific power requirement.
▪ ECM can machine faster and has a low thermal surface
damage depth.
▪ USM and AJM have very low material removal rates
(MRR) combined with high tool wear and are used non
metal cutting.
▪ LBM and EBM are, due to their high penetration depth
can be used for micro drilling, sheet cutting and welding.
▪ CHM is used for manufacture of PCM and other
shallow components.
▪
Some Observations
EDM has the lowest specific power requirement and
can achieve sufficient accuracy.
 ECM has the highest metal removal rate, MRR.
 USM and AJM have low MRR and combined with high
tool wear, are used for non-metal cutting.
 LBM and EBM have high penetration rates with low
MRR and, therefore, are commonly used for micro
drilling, sheet cutting, and welding.
 CHM is used for manufacturing PCB and other shallow
components.
 PAM can be used for clean, rapid cuts and profiles in
almost all plates up to 20 cm thick with 5 ̊to 10 ̊ taper.

Limitations of NTM
Expensive set up, low MRR and skilled labor
required.
▪ The limitation of electrical machining methods
is that the work material must be an electrical
conductor. Also, consumption of electrical
energy is very large.
▪ The NTM which have not been proved
commercially economical are: USM, AJM, CHM,
EBM and PAM.
▪
Problem
How will you decide to recommend specific advanced machining
processes for A) cutting a glass plate into two pieces, B) making a
hole in a mild steel workpiece?
Solution:
A) Cutting of a glass plate into two pieces:
▪ Glass is electrically non-conductive hence certain processes (ECM,
EDM, PAM, EBM) are ruled out because they can’t be employed for
electrically non-conductive workpieces.
▪ LBM can be ignored being an expensive process.
▪ Chemical machining need not be considered because it is for very
special applications.
▪ WJM is usually for comparatively softer materials.
▪ AJM, AWJM and USM can be applied. Which one to use will also
depend on the size of the workpiece, and the kind of the accuracy
required.
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Continue solution
B) In case of a hole in M.S., one can proceed as follows:
▪ More suitable for comparatively harder materials, one can drop
AJM, USM and AWJM.
▪ Being electrically conductive, ECM, EDM, LBM, EBM, and PAM can
be employed. At this point, one should know the requirements of
the hole in terms of dimensions, tolerances and surface integrity. If
it is not a micro hole one can easily adopt ECM or EDM. If high
surface integrity is required, ECM should be used, and so on.
Thus, by elimination process one should arrive at the particular
process to be used.
Question 1
Which of the following processes has very high
material removal rate efficiency?
a. Electron beam machining
b. Electrochemical machining
c. Electro discharge machining
d. Plasma arc machining
Question 2
Arrange the processes in the increasing order of their maximum
material removal rate.
• Electrochemical Machining (ECM)
• Ultrasonic Machining (USM)
• Electron Beam Machining (EBM)
• Laser Beam Machining (LBM) and
• Electric Discharge Machining (EDM)
a.
USM, LBM, EBM, EDM, ECM
b.
EBM, LBM, USM, ECM, EDM
c.
LBM, EBM, USM, ECM, EDM
d.
LBM, EBM, USM, EDM, ECM
Question 3
Consider the following statements in relation to the
unconventional machining processes:
1.
Different forms of energy directly applied to the piece to have
shape transformation or material removal from work surface.
2.
Relative motion between the work and the tool is essential.
3.
Cutting tool is not in physical contact with work piece.
c.
1 and 2 only
1, 2 and 3 only
2 and 3 only
d.
1 and 3 only
a.
b.
Question 4
Which one of the following statements is correct
in respect of unconventional machining processes?
a. The cutting tool is in direct contact with the job.
b. The tool material needs to be harder than the job
material.
c. The tool is never in contact with the job.
d. There has to be a relative motion between the tool
and the job.
Question 5
Match List I (Processes) with List II (Tolerances obtained)
and select the correct answer using the codes given below
the Lists:
Processes
A.
B.
C.
D.
a.
b.
c.
d.
Plasma arc machining
Laser beam machining
Abrasive jet machining
Ultrasonic machining
A
B
C
D
4
1
3
2
3
2
4
1
4
2
3
1
3
1
4
2
Tolerance obtained
1.
2.
3.
4.
7.5 micron
25 micron
50 micron
125 micron