Basic Principles of Physical Metallurgy

Performance of metals and alloys in actual service is primarily determined by the nature distribution of microconstituents present. These can be seen under micro scope using suitable metallographic techniques which will be discussed in detail in subsequent lectures. However, in order to interpret them it is necessary to have some eleme-ntary knowledge about the evolution of structure in metals and alloys as they solidify from melt and how this can be altered by various thermal and mechanical processes to suit specific application. Metals and alloys have certain unique properties which are characteristic of their bond-ing and crystal structures. As a consequence a wide range of microstructures having different properties could be developed even in the same metal or alloy. The subject of physical metallurgy primarily deals with these. In this
lecture I shall try to present some of the basic concepts of this subject so that it helps you understand and interpret the information hidden within the microstructure.