Question

1. Represent with drawing the Miller indices of the slip systems of the BCC structure?

Answer 1

• Miller Indices are used to represent the directions and the planes in a crystal • Miller Indices is a group of smallest integers which represent a direction or a plane [012] 100) (110

The stress strain graph for a ductile material is given below:

Plastic region X Ultimate tensile strength Stress Yield tensile strength Elastic region Strain

Crystals can have various structures: FCC, BCC and HCP are common to metals Unit Cell Cubic FCC 400um BCC Space Lattice Hexagonal HCP

Coordination # = 8 Atomic Packing Factor = 0.68 Body-Centered Cubic (BCC)

Close-packed Planes & Miller Indices Slip systems in metals Crystal Structure Slip plane Slip direction Number of slip systems FCC 12 pm <II 3 (primary) BCC 110) 12 primary 11121./123) <II> 36 secondary) !! HCP

Close-packed planes: BCC Primary Slip Plane: (110) = normal vector bec Primary Slip Directions: <111>