Engineering Materials Lab - Quiz 1

Question 1

Hardness:

Answer 1

Resistance of metal to plastic deformation usually caused by indentation

Question 2

Hardness also refers to

Answer 2

Stiffness, temper, resistance to scratching, abrasion or cutting

Question 3

The greater the hardness, the greater

Answer 3

Resistance it has to deformation

Question 4

The tensile strength can be determined from hardness data?

Answer 4

True

Question 5

5 types of Hardness tests:

Answer 5

Brinwell, Rockwell, Vickers, Knoop, MOHS

Question 6

Hardness tests involve the depth at which a ball will sink into a metal under a given load for a period of time

Answer 6

True

Question 7

Vickers number =

Answer 7

1.854(F/D^2)

Question 8

Diamond pyramid at 136 degrees?

Answer 8

Vickers

Question 9

Creep:

Answer 9

a time-dependent and permanent deformation of materials when subjected to a constant load at a high temperature (>0.4 T.m) - Turbine blades, steam generator

Question 10

Primary:

Answer 10

work-hardening is happening / rate decreases with time

Question 11

Secondary:

Answer 11

rate is constant / balance of work-hardening and recovery

Question 12

Tertiary:

Answer 12

rapidly accelerating strain rate to failure, causing internal cracks, voids, grains

Question 13

With increasing stress or temperature:

Answer 13

• The instantaneous strain increases
• steady-state creep rate increases
• time to rupture decreases