Mechanical Behaviour of Metals and Alloys

Abstract

In service, metallic components are required to withstand stresses without failure and their ability to do this is dependent on their mechanical properties. Under the influence of stress metal undergoes deformation and finally fails in ductile mode. Deformation occurs by sliding of atoms along slip planes under the influence of stress and by movement of dislocations. Any hindrance in dislocation movement would increase the strength and this principle is used to increase the strength of material. In this chapter, the basic mechanism of plastic deformation, ductile to brittle transition, strengthening mechanisms and important mechanical properties for practical use have been discussed. These include yield and breaking strength, fracture and fracture mode, and toughness. The tests to be performed to determine these properties including hardness have been described. The chapter also includes fatigue failure of metals and the problem of irreversible damage caused due to creep at high temperatures.