This document discusses the classification and properties of engineering materials. It describes 8 categories of material properties - mechanical, thermal, electrical, magnetic, chemical, optical, physical and technological. Mechanical properties include strength, elasticity, plasticity, rigidity, ductility, malleability, resilience and hardness. Alloys are formed by combining metals for improved strength or corrosion resistance. Examples of alloys discussed are aluminum alloys like aluminum-silicon and aluminum-copper, copper alloys like copper-tin, and stainless steel. Common applications of these alloys are also mentioned.

1. ENGINEERING MATERIALS

2. CLASSIFICATION OF ENGINEERING MATERIALS

5. Properties of Materials
1. Mechanical Properties
2. Thermal Properties
3. Electrical Properties
4. Magnetic Properties
5. Chemical Properties
6. Optical Properties
7. Physical Properties
8. Technological Properties

6. Mechanical Properties
1. Strength:
It is the capacity to withstand destruction when external
forces are applied.
2. Elasticity:
It is the ability of a material to regain its original shape
and size when external force causing the deformation is
removed.
3. Plasticity:
It is the ability of a material to undergo permanent
deformation.
4. Rigidity:
It is the ability of a material to resist the deformation.
5. Ductility:
It is the ability of a material to draw out into thin wires.

7. 6. Malleability:
It is the ability of a material to be flattened into thin sheets.
7. Resilience:
It is the ability of a material to absorb energy.
8. Hardness:
It is the ability of a material to resist scratching, abrasion etc
9. Brittleness:
It is the property of breaking out without much deformation.

8. Alloys
• Alloy is a metal made by combining two or more metallic
elements, especially to give greater strength or resistance
to corrosion.
• The metal present in the alloy in largest proportion is
called base element.
• All other elements present in the form of metal or non
metal are called alloying elements.

9. Aluminium Alloys
• The aluminium alloys are hard and strong and retain the light
weight of aluminium
 Aluminium-Silicon alloys
 Aluminium-Copper alloys
 Aluminium-Magnesium alloys
Application of aluminium alloys
 Used in the production of cars and engine parts.
 Aircrafts, military, commercial, industrial, medical, residential
and manufacturing applications

10. Copper alloys
• Copper alloys are useful on account of their heat and electrical
conductivity, good cold and hot working properties.
• Copper-Tin Alloys
Used in airtight seals
Used for sleeve bearing
Used in the manufacture of all types of electrical
equipment.

11. Stainless Steel
• Stainless steel has great strength and toughness and good
resistance to corrosion and heat.
 Used for many commercial applications such as watch
straps
 All type of surgical and dental instruments
 Household appliances etc