Properties of Materials | SOM | Post Number II

I). Properties Of Materials: 

i) Elasticity: 

• It is the property by  virtue of which a material deformed under the load is enabled to return to its dimension when the load is removed
• E.G. Rubber, Steel, Aluminium, Copper & etc. with certain Elastic Limits.

ii) Plasticity:

• The characteristics of materials by which it undergoes inelastic strain beyond those at the elastic limit are known as plasticity.

iii). Ductility:

• It is the property which permits a material to be drawn out longitudinally to a reduced section, under the action of tensile force.

iv) Malleability:

• It is the property of a material which permits the material to be extended in all direction without rupture. 
• It possesses the high degree of plasticity, but no necessarily great strength.

v) Toughness:

• It is the property of the material which enables it to absorb energy without fracture.

vi) Hardness:

• An ability of a material to resist or surface abrasion.
• Berinnel Hardness Test (BHT) is used to check hardness.

vii) Strength: 

• Property enables the material to resist fracture under load.

viii) Ultimate Strength:

• The load required to cause a fracture, divided by area of the test specimen.

ix) Creep:

• Permanent deformation which reordered with the passage of time at constant loading. 
• It is plastic deformation in nature.
• The temperature at which creep is uncontrollable is called homologous temperature.  

x) Fatigue:

• Due to cyclic or reverse cyclic loading fracture failure may occur if total accumulated.
• Strain energy exceeds the toughness. 
• Fatigue causes rough fractured surface ever in ductile metals.

xi) Resilience:

• Total elastic strain energy which can be stored in the given volume of metal & can be released after unloading.