MNIT MET-225
Course Code: MET-225
Machining Science &
Machine Tools
-Dr. Anup Malik
anup.mech@mnit.ac.in
Most of the images are courtesy of the book “Manufacturing Engineering and Technology” by
Serope Kalpakjian & Steven R. Schmid.
Few were adopted from “ Fundamentals of Modern Manufacturing – Materials, Processes
and Systems” by Mikell P. Grover.
Images collected from Wikipedia and google images were also used.
1
MNIT MET-225
MET-225 : Machining Science & Machine Tools
Course Objective:
• Introduce fundamental concepts of Science behind machining
• Introduce fundamental concepts of Machine tools, CNC
machines their part programming
• Economics of machining & maintenance of machine tools
You will learn about:
• Mechanics of metal cutting & machinability
• Cutting tools geometry, tool material, tool wear & tool life
• Cutting fluids and their selection during machining
• Various machine tools, CNC machines & their part
programming
• Economics of machining & maintenance of machine tools
2
MNIT MET-225
MET-225 : Machining Science & Machine Tools
This course will help you to:
• Proper selection of a machining process & machine tools
• Identify various type of cutting tools & their applications in
the industry
• Choose suitable cutting fluid for required machining
• Operate various CNC machines and develop a programming
code for production of a part/component
• Calculate machining economics
• How to effectively run a machine shop.
3
MNIT MET-225
MET-225 : Machining Science & Machine Tools
Syllabus L3T1 P0 4 Credits
Unit 1
Materials and Geometry of Cutting Tools: Introduction,
Desirable Properties of Tool Materials, Characteristics of Cutting
Tool Materials, Cutting tool geometry, Chip flow direction, Tool
angles specification systems, Cutting parameters and Tool
geometry, Index able inserts, chip breakers, Tools of unusual
geometry.
4
MNIT MET-225
MET-225 : Machining Science & Machine Tools
Syllabus L3T1 P0 4 Credits
Unit 2
Mechanics of Metal Cutting: Merchant's circle diagram-
determination of cutting and thrust forces; Coefficient of friction;
shear plane angle, Velocity and force relationship, shear stress
and strain and strain rate in orthogonal cutting, stress distribution
along rake face, theories of Lee and Shaffer’s, Oxley’s, etc.
Cutting force measuring techniques i.e. dynamometer.
5
MNIT MET-225
MET-225 : Machining Science & Machine Tools
Syllabus L3T1 P0 4 Credits
Unit 3
Thermal aspects in Machining: Regions of heat generation;
Heat In the Primary Shear Zone, Heat at the Tool/work Interface,
Heat Flow at the Tool Clearance Face, Average shear plane
temperature; Average chip-tool interface temperature; method of
tool temperature measurement, temperature distribution in tool
Cutting Fluid: Types and composition of cutting fluids, selection
of cutting fluid.
6
MNIT MET-225
MET-225 : Machining Science & Machine Tools
Syllabus L3T1 P0 4 Credits
Unit 4
Tool Wear, Tool Life and Machinability: Tool wear
mechanisms, Types of tool damage during cutting, Wear and
chipping characteristics of different tool materials, Tool wear
equations, tool failure criteria, Tool life equations, Effect of
process parameters on Tool life, Tool life testing, Machinability,
Surface finish and surface integrity.
7
MNIT MET-225
MET-225 : Machining Science & Machine Tools
Syllabus L3T1 P0 4 Credits
Unit 5
Machine Tools: types and classification; NC, CNC etc., static,
dynamic and thermal consideration in machine tools.
8
MNIT MET-225
MET-225 : Machining Science & Machine Tools
Syllabus L3T1 P0 4 Credits
Unit 6
CNC Machines: Introduction to CNC Systems, Fundamental
aspects of machine control, types of CNC machines,
Constructional Features of CNC Machines: Structure, Drive
Mechanism, gearbox, Main drive, feed drive, Spindle Motors,
Axes motors. Timing belts and pulleys, Spindle bearing, Slide
ways, Re-circulating ball screws – Backlash measurement and
compensation, linear motion guide ways, Tool magazines, ATC,
APC, Chip conveyors. Retrofitting of Conventional Machine
Tools, Retrofitting of conventional machines with CNC.
9
MNIT MET-225
MET-225 : Machining Science & Machine Tools
Syllabus L3T1 P0 4 Credits
Unit 7
Part Programming: Part Program Terminology-G and M Codes
– Types of interpolation Methods of CNC part programming –
Manual part programming – Computer Assisted part
programming – STEP NC programming, CNC part programming
using CAD/CAM-Introduction to Computer Automated Part
Programming.
10
MNIT MET-225
MET-225 : Machining Science & Machine Tools
Syllabus L3T1 P0 4 Credits
Unit 8
Economics and Maintenance: Factors influencing selection of
CNC Machines, Cost of operation & commissioning of CNC
Machines, Maintenance features and Preventive Maintenance of
CNC Machines.
11
MNIT MET-225
MET-225 : Machining Science & Machine Tools
Text Books & References:
1) Manufacturing Engineering and Technology by Sepore Kalpakjian
2) Metal cutting theory and practice by A. Bhattacharya
3) Metal Cutting & Machine Tools by P N Rao
4) Manufacturing Engineering and Technology by Mikel P. Groover
5) Metal Cutting Principles by Milton C Saw
6) Machining Sciences by Amitabh Ghosh and A. K. Mallik
7) CNC Machines by M.S. Sehrawat and J.S. Narang
8) CNC Programming Handbook by Smid Peter
9) Production Technology by HMT
12
Manufacturing
What is manufacturing?
The word manufacture is derived from two Latin words,
manus (hand)
&
factus (make);
combination means “made by hand”
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. The processes to
accomplish manufacturing involve a
combination of machinery, tools,
13
power, and labor.
Manufacturing
What is manufacturing?
The word manufacture is derived from two Latin words,
manus (hand)
&
factus (make);
combination means “made by hand”
Economically, manufacturing is the
transformation of materials into
items of greater value by means of
one or more processing and/or
assembly operations. The key
point is that manufacturing adds
value to the material by changing
its shape or properties, or by
combining it with other materials
14
that have been similarly altered.
Manufacturing Process
What is manufacturing process?
A 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. A
manufacturing process is usually carried out as a unit operation,
which means that it is a single step in the sequence of steps
required to transform the starting material into a final product.
Manufacturing operations can be divided into two basic types:
(1) Processing operations and
(2) Assembly operations.
15
Manufacturing Process
What is manufacturing process?
A processing operation transforms a work material from one state
of completion to a more advanced state that is closer to the final
desired product. It adds value by changing the geometry,
properties, or appearance of the starting material.
An assembly operation joins two or more components to create a
new entity, called an assembly, subassembly, or some other term
that refers to the joining process (e.g., a welded assembly is called
a weldment).
16
Historical Development of Materials, Tools & Manufacturing Processes
17
Historical Development of Materials, Tools & Manufacturing Processes
18
Historical Development of Materials, Tools & Manufacturing Processes
19
Classification of Manufacturing Process
20
Shaping Process
Casting and molding processes start with a work material heated to a fluid or
semifluid state. The process consists of: (1) pouring the fluid into a mold cavity
and (2) allowing the fluid to solidify, after which the solid part is removed from the
mold.
21
Casting Processes
22
Particulate Processing
Particulate processing: (1) the starting material is powder; the usual process
consists of (2) pressing and (3) sintering.
23
Deformation Process
Some common deformation processes:
(a) forging, in which two halves of a die squeeze the workpart, causing it to
assume the shape of the die cavity; and
(b) extrusion, in which a billet is forced to flow through a die orifice, thus taking
the crosssectional shape of the orifice.
24
Bulk-Deformation Processes
25
Sheet-Metal-Forming Processes
26
Polymer-Processing Processes
27
Metal Removal Process
Common machining operations:
(a) turning, in which a single-point cutting tool removes metal from a rotating
workpiece to reduce its diameter;
(b) drilling, in which a rotating drill bit is fed into the work to create a round hole;
and
(c) milling, in which a workpart is fed past a rotating cutter with multiple edges.
28
Machining Processes
29
Joining Processes
30
