Crystal Structure of Different Metals and its effect on the Material Property of Metals

In the last two lectures, we have discussed about some of the very common crystal structures. You might have noted that the metals mostly have either of the three crystal structures:

a. Face Centred Cube (FCC)
b. Body Centred Cube (BCC)
c. Close Packed Hexagon (CPH) also sometimes referred as HCP

Rarely, you will find metals having simple cubic or tetragonal crystal structure and most of them are not important from the mechanical application point of view.

The Table below shows the crystal structures of some of the common metals arranged in the order of increasing density. The HCP crystals are farther grouped into two groups, Group A having c/a ratio << 1.633 and Group B having c/a ratio equal to or higher than 1.633.