ENG1001B Week 11

For an edge dislocation, what is the relationship between direction of the applied shear stress and the resulting dislocation line motion?

• parallel

• perpendicular

• neither

For a screw dislocation, what is the relationship between direction of the applied shear stress and the resulting dislocation line motion?

• parallel

• perpendicular

• neither

For a mixed dislocation, what is the relationship between direction of the applied shear stress and the resulting dislocation line motion?

• parallel

• perpendicular

• neither

A slip plane is a crystallographic plane on which slip occurs most ________ and has a ________ planar density.

• easily, low

• easily, high

• strenuously, low

• strenuously, high

How many total slip systems does a FCC lattice structure possess?

• 3

• 6

• 12

• 15

The number of available slip systems of a metal depends on...

• close-packed planes

• close-packed directions

• stacking sequence

• atomic packing factor

Is it possible for two screw dislocations of opposite sign to annihilate each other?

• Yes, if their dislocation lines are parallel

• Yes, if their dislocation lines are perpendicular

• No

Typically, dislocations occur relatively easily in metals, but relatively difficult in ceramics. This is because...

• Metals have non-directional bonding

• Ceramics have non-directional bonding

• Metals have fewer directions for slip

• Ceramics tend to have ionic bonds & electrostatic repulsion