Transcript MENG 286 MATERIALS SCIENCE

Week 1
Introduction to Manufacuring
MANUFACTURING TECHNOLOGY
What Is Manufacturing
 Derived from Latin words:
Manus (Hand); Factus (Make)
Means: Made by hand
Manufacturing- Definition
 Technological: Application of physical and chemical
processes to alter the geometry, properties and/or
appearance of a given starting material to make parts
or product.
 Economic: Transformation of materials into items of
greater value by means of one or more processing
and/or assembly operations.
Shape Change
Raw
Material
Physical/Chemical
Processes
Value Addition
Final
Product
Manufacturing Vs Production
 The terms manufacturing and production are often
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interchangeably used
Production has a broader meaning than manufacturing
Term Production is used to indicate the output of
continuous processes: oil production, cement
production, chemical production. Term manufacturing is
not used normally.
In case of making discrete (separate) components as
automobile/ aero-plane parts, usually the term
Manufacturing is used. However, production is also
acceptable in this case.
Involvement of hand is more in manufacturing than in
production
Materials in Manufacturing
1. Metal: Term metal is derived from Greek word métallon,
which means an open excavation or pit from which stone is
obtained by digging, cutting, or blasting.
It is an element or compound or alloy that is a good
conductor of both electricity and heat. Metals are usually
shiny, malleable and ductile.
Types: Ferrous (iron based); Non-ferrous
2. Ceramic: A compound containing metallic & non-metallic
(Oxygen, Nitrogen, Carbon) elements
Types: Crystalline ceramics ; Glasses
Materials in Manufacturing- Contd
3. Polymer: Compound formed of repeating structural
units called mers whose atoms share electrons to form very large
molecules.
- Polymers consist of C plus one or more other elements (H, O, Cl)
Types: Thermoplastic (Polythene, Nylon); Thermosetting (Resins,
Epoxies); Elastomer (rubber, silicone).
4. Composites: Mixtures of other three types
- A material consisting of two or more phases that are processed
separately and then bonded together to achieve properties superior
to those of its constituents.
- The usual structure of a composite consists of particles or fibers
of one phase (homogeneous mass of material that has distinct
properties) mixed with other, called matrix.
Mechanical Properties of Engineering
Materials
 The properties of a material which determine its
behavior when it is subjected to mechanical stresses
 Include strength, modulus of elasticity, hardness,
toughness, ductility, etc
 Objective in Design Phase -> Withstand the stresses
without significant changes in geometry
 Objective in Manufacturing Phase -> Apply the
stresses that exceed the yield strength so as to
change the shape of the part