manufacturing exam questions

Question 1

how do you measure hardness of material?

Answer 1

• clean specimen
  3 types of tests:
  1. indent
  2. scratch
  3. microhardness

Question 2

how would a brittle and ductile material of the same toughness differ on a stress strain graph?

Answer 2

brittle:
-high stress, low strain
-steep slope before sudden drop off
-little to no plastic deformation
-graph will end suddenly
ductile:
-medium stress, high strain.
-distinct point where plastic deformation begins.
-plastic deformation stage lasts for a while