Mechanical Properties of Metals
Mechanical properties are the characteristic responses of a material to applied forces. Knowledge of mechanical properties of materials is essential in order to construct a mechanically sound structure such as a bridge on the river. Mechanical properties can be determined by conducting experimental tests on the material samples. Some important mechanical properties of materials are: strength (in tension, compression, shear, bending and torsion), stiffness (strength), ductility, impact strength, hardness and toughness.
1. Strength
The Strength of a material may be defined as the ability of the material to sustain loads without undue distortion or failure. Material should be adequately strong when subjected to tension, compression, shear, bending or torsion as per the intended use. For example, the crankshaft of an automobile should have sufficient torsion strength.�
2. Stiffness
Stiffness is the ability of a material or shape to resist elastic deflection. For identical shapes, the stiffness is proportional to the modulus of elasticity. A material which deforms less under a given load is stiffer than one which deforms more.
3. Ductility
Ductility refers to the capacity of a material to undergo deformation under tension without rupture as in a wire drawing operation.�
4. Impact Strength
Impact strength is the strength of a material when subjected to high rates of loading, usually in bending, tension or torsion. The amount of energy required to fracture the material by a single blow is measured by means of a Charpy impact test.
5. Hardness
Hardness is the resistance of a material to plastic deformation usually by indentation. However, the term may refer to stiffness or refer to resistance to scratching, abrasion or cutting. Tests, such as Vickers, Briell and Rockwell, are generally employed to measure hardness.�
6. Toughness
Toughness refers to the ability of a material to withstand bending or the application of shear stresses without fracture. By this definition, copper is extremely tough but cast iron is not.
Materials Sustain Loads On Tension
Materials Sustain Loads On Shear
Materials Sustain Loads on bending
Materials Sustain Loads on torsion