With the help of appropriate diagrams explain material Tough

With the help of appropriate diagrams, explain material Toughness for the three primary classes of materials. Give an example of an engineering application requiring high material toughness. Label your diagram carefully.

Solution

Toughness:

It is the ability of the materials to withstand bending or it is the application of shear stresses without fracture, so the rubbers and most plastic materials do not shatter, therefore they are tough. For example, if a rod is made of high-carbon steel then it will be bend without breaking under the impact of the hammer, while if a rod is made of glass then it will broken by impact loading

Increasing the strength of a material is useful only as long as it remains plastic and does not fail by fast fracture. The resistance to the propagation of a crack is measured by the fracture toughness.

Impact tests consist of striking a suitable specimen with a controlled blow and measuring the energy absorbed in bending or breaking the specimen. The energy value indicates the toughness of the material under test.

The temperature of the specimen at the time of making the test also has an important influence on the test results.The embrittlement of low-carbon steels at refrigerated temperatures, and hence their unsuitability for use in refrigeration plant and space vehicles.