EM-226 Materials and Manufacturing
Processes
Instructor: Dr. Khurram Kamal
Course Outline
Engineering Materials
• Desired Engineering Properties
• Concept of Structure
• Metals and Alloys
• Phase Diagrams
• Ceramics
• Polymers
• Composites
• Semiconductors
• Materials Characterization
• Scanning Probe Microscopy
• Non-Destructive Testing
• Material Selection
• Failure Analysis
Manufacturing Processes
• Manufacturing Systems
• Foundry Practice and Modern Casting
• Machining Processes
• Welding
• Brazing and Soldering
• Non-traditional Manufacturing Processes
• Heat Treatment
• Electronic Fabrication
• Rapid Prototyping
Recommended Books
• Elements of Material Science and Engineering by Van
Vlack, Addison Wesley Publishing Co., Latest Edition2
• Introduction to Physical Metallurgy by Sidney H. Avner,
McGraw Hill publishing Co., Latest Edition.
• Engineering with Polymers by P.C. Powell. , Latest
Edition.
• Manufacturing Processes by Amstead, Begeeman and
Ostwald, John Wiley & Sons, Latest Edition.
• Materials and Processes in Manufacturing by E. Paul
Degarmo, J. Black, Ronald A. Kosher. , 10th Edition.
Marks distribution
50% Finals
30% First-term and mid-term
10% Quiz
10% Project Assignment + Report
What is manufacturing?
The word manufacturing, is derived from the Latin
word “manu factus”, meaning made by hand. The
word manufacture first appeared in 1567, and the
word manufacturing appeared in 1683. In modern
sense, manufacturing involves making products from
raw materials by means of various processes,
machinery, and operations, through a well-organized
plan for each activity required. In a simpler way,
manufacturing is a method/technique used to convert
input in any form by the use of certain processes into a
valuable output, going through a series of
transition/value-adding processes.
Types of manufactured goods
• Manufactured goods are classified into two
types
• Producer Goods: are used to manufacture
either producer or consumer goods.
• Consumer Goods: are those purchased directly
by the consumer or the general public.
Why manufacturing?
• Manufacturing is critical to a country’s economic
welfare and standard of living to its people.
• The standard of living in any society is determined,
primarily , by the goods and services that are
available to its people.
• Manufacturing companies contribute about 20% of
the GNP, employ about 18% of the workforce, and
account for 40% of the exports of the United States.
• In most cases, materials are utilized in the form of
manufactured goods.
Manufacturing Process
• A manufacturing process converts unfinished materials
to finished products, often using machines or machine
tools.
• For example, injection molding, die casting, stamping,
arc welding, are commonly called processes or
manufacturing processes.
• The term process often implies a sequence of steps,
processes, or operations for production of goods and
services.
• A machine tool is an assembly of related mechanisms
on a frame or bed that together produce a desired
result.
• Generally, motors, controls, and auxiliary
devices are included.
• Cutting tools and workholding devices are
considered separately.
• A machine tool may do a single process (e.g.,
cutoff saw) or multiple processes, or it may
manufacture an entire component. Machine
sizes vary from a tabletop drill press to a 1000ton forging press.
Olympic Medal
MATERIAL CHARACTERISTIC AND
SELECTION
• In any finished product, it normally involves one or more
than one type of material. Material can be obtained in
either their original form or artificial form. There are lot of
material involved in engineering application, alloys alone
already consists of thousands of types. Not only alloys, the
same with ceramics and polymers, their application is also
very wide in engineering application.
• Nowadays, more and more materials are being developed
and researched to suit a specific application. Thus, an
engineer has no choice but to know how to choose/select
the best possible alternative for production to achieve their
needs.
Material Selection
• Every produced product must be able to function
as it is designed in a proper working condition for
an acceptable period of time without failure.
• Material selection play an important role in this,
because selection of material will determine the
characteristic, function, and also the cost of the
product.
• There are few crucial factors that are needed to
be considered for material selection, these are:
• Suitability of material in term of function usage of material in
finished goods and also processing of the material to produce the
product.
• Reliability of material in term of ability/repeatability in producing
desired dimension, surface texture, and tolerances.
• Manufacturability of the material, the consideration if it can be
formed/casted/welded/heat-treated/etc. easily as desired.
• Processing effect towards the final characteristics of the material
also should be considered, as it might affect the final
• quality of the products, life of the products, and performance of the
products.
• Durability of the material is always in the consideration as it will
somehow determine how long the product can last, especially in
some areas like wear with time, compatibility with other material,
safety factors, etc.
• Availability of material and the ease to obtain supply of
material in reasonable cost should be considered during
material selection. This is to prevent your production from
facing the possibility in shortage of materials, or running at
a material costing.
• Manufacturing cost should be reasonable in order to stay
competitive with the competitors. Thus, various
manufacturing processes should be considered in order to
get the best possible methods that suit your production.
• Waste elimination of material should be considered in
order to avoid illegal disposable of material. If possible, go
for some material which can be recycled.
Engineering Materials
• Materials used in engineering application can
basically divided into three categories;
• Metals
• Ceramics
• Polymers
• Composites
• The common metallic materials include iron,
copper, aluminum, magnesium, nickel,
titanium, lead, tin, and zinc as well as the
alloys of these metals, such as steel, brass,
and bronze.
They possess the metallic properties of luster,
high thermal conductivity, and high electrical
conductivity; they are relatively ductile; and
some have good magnetic properties.
Physical and mechanical properties
• A common means of distinguishing one material from
another is through their physical properties.
• These include such features as density (weight); melting
point; optical properties (transparency, opaqueness, or
color); the thermal properties of specific heat, coefficient of
thermal expansion, and thermal conductivity: electrical
conductivity; and magnetic properties.
• In some cases, physical properties are of prime importance
when selecting a material, however, material selection is
dominated by the properties that describe how a material
responds to applied loads or forces.
• These mechanical properties are usually
determined by subjecting prepared specimens to
standard test conditions.
• When using test results, however, it is important
to remember that they apply only to the specific
conditions that were employed. The actual
service conditions of engineered products rarely
duplicate the conditions of laboratory testing, so
considerable caution should be exercised when
applying test results.
STRESS AND STRAIN
• When a force or load is applied to a material, it deforms or distorts
(becomes strained), and internal reactive forces (stresses) are
transmitted through the solid.
• For example, if a weight, W, is suspended from a bar of uniform
cross section and length, the bar will elongate by an amount ∆L. For
a given weight, the magnitude of the elongation, ∆L, depends on
the original length of the bar.
• The amount of elongation per unit length, expressed as e = ∆L /L, is
called the unit strain.
• Although the ratio is that of a length to another length and is
therefore dimensionless, strain is usually expressed in terms of
millimeters per meter, inches per inch, or simply as a percentage.
• Application of the force also produces reactive stresses,
which serve to transmit the load through the bar and on to
its supports.
• Stress is defined as the force or load being transmitted
divided by the cross-sectional area transmitting the load.
• The stress is S = W/A, where A is the cross-sectional area of
the supporting bar. Stress
• is normally expressed in mega pascals (in SI units, where a
pascal is 1 newton per square meter)
• meter) or pounds per square inch (in the English system).
• In figure, the weight tends to stretch or lengthen the bar, so
the strain is known as a tensile strain and the stress as a
tensile stress.
• Other types of loadings produce other types
of stresses and strains.
• Compressive forces tend to shorten the
material and produce compressive stresses
and strains.
• Shear stresses and strains result when
two forces acting on a body are offset with
respect to one another.
Tensile Strength Test
Engineering stress-strain curve
Strength
Strength: is a material’s ability to withstand a
force without failure. Depending on the type
of forces applied, each and every material will
have different strength level for different type
of strength test. For example, a material might
be having a good tensile strength but weak
hardness strength.
Elasticity
• Elasticity :is the ability of material to
return to its original condition
whenever a force applied is released.
Plasticity
• Plasticity: is the ability of material to
form under pressure and remain in
its new shape whenever the pressure
is released.
Ductility
• Ductility: is the ability of material to
deform plastically without fracture.
• Indication of ductility can be given by
percentage reduction in the area
i.e. (A o - A f )/ A o x 100%
Brittleness
• Brittleness: If a material fails with
little or no ductility then it is said to
be brittle. Thus brittleness can be
seen as opposite to ductility.