Different Mechanical Properties of Materials

A design engineer must have a good concept about the mechanical properties of materials. Different manufacturing processes and heat treatment can change the properties of materials. A good design engineer should have a good knowledge about these properties.


Engineering materials are divided in the following divisions -

1. Metal and Metal Alloys . Example : Iron, Copper, Nickel etc.
2. Non- Metals . Example : Ceramics. rubber, glass etc.

Please read :

• What is Stress and Strain ?
• Mechanical Properties of Mild Steel 

Important Mechanical Properties of Materials  are Described Below :

a. Strength: This term describes the ability of the material to resist external forces. Without Yielding (Yield point is the point at which plastic deformation starts)breaking.

b. Stiffness: This is measured by the modulus of elasticity.  It is the ability of the material to resist deformation when stress is applied. 

c. Elasticity: Elasticity is the ability of the material to regain its original form when the external force is removed. Steel's elasticity is greater than rubber. 

d. Plasticity: This property is the ability of the material to deform permanently. It helps to shape the material to make into thin plates or molds. 

e. Ductility: Ductility is the property of the material which makes it enable to become thin wire with the application of tensile force (equally intense pull). The mechanical properties of mild steel show that it is very ductile. 

f. Brittleness:  Brittleness refers to the property of the material due to which a material breaks with association of very little distortion. Brittle materials are glass, ceramic, cast iron. 

g. Malleability: It helps the material to be converted to thin sheets or plates. It is actually a special case of ductility. Malleable materials are prone to plastic deformation. They need not be strong. Lead, soft steel, copper etc are very much malleable which are used in the engineering process. 

h. Toughness: It is the ability of the material to prevent fracture when high impact load and shocks are applied. Toughness is reduced when the material is heated. 

i. Resilience: This property is also needed for resisting shocks and impacts. Resilience refers to the energy absorbed within the elastic limit per unit volume. 

j. Creep: This property of the material states the phenomenon of permanent and slow deformation of the material when subjected to constant stress at high temperatures. IC engines, boilers etc. are designed keeping this term in head. 

k. Fatigue: when material is subjected to repeated loads, it fails before reaching the yield point. This type of failure is called fatigue. At first cracks developed in the machine parts in microscopic level and with time the probability of failure increases. 

l. Hardness: Hardness has different meanings. Resistance to wear, deformation and scratches are expressed by hardness.

Mechanical properties of materials differ in metals and non metals. Metallurgical and Mechanical Engineers should have good knowledge about material properties.