Strength:- This is the property of metals that can withstand or support the external force or load without rupture. it is a very important property of metals.
The Mechanical Strength is mainly divided into two parts which is depending on the value and the nature of stresses.
- Depending upon the nature of value of stress:-
- Elastic Strength:- The value of load corresponding to the transition from elastic to plastic range.
- Plastic Strength:- The value of load corresponding to the plastic range and rupture as shown in above fig. It is also called ultimate strength. The ratio of ultimate stress to the working stress of a metal, is called factor of safety.
2. Depending upon the nature of stress, the strength of a metal by :
A) Tensile Strength:- It is the value of load applied to break if off by the pulling it outwards into two pieces. It is express in N/mm2 or MN/m2 or Mpa.
- For the testing of tensile strength of metal, select the tensile strength test machine as per the job strength and machine specification.
- After that, mark on the workpiece as per testing procedure and then clam on both the jaw with tight & accurate fitting, there one jaw movable and other always fixed on the bottom side.
B) Compressive strength:- The value of load applied to break it off by crushing. It is express in N/mm2 or MN/m2 or Mpa.
C) Shear Strength:- The value of load applied tangentially tp shear it off across the resisting section. Two opposing forces are applied which share the material at its weak point.
D) Bending Strength:-The value of load to break it off by the bending it across the resisting section.
E) Torsional Strength:- The value of load to break it off by the twisting it across the resisting section.
Aluminium Metals 