2017 HL Section B Question 4 (Thermal Equilibrium Diagram)

Question 1

Describe the process of age hardening

Answer 1

work piece is heated and soaked to dissolve alloyed particles

ageing occurs at room temperature or elevated temperature depend on the piece

work piece is heated to an intermediate temperature to reduce precipitation

Question 2

outline two benefits of the age hardening process

Answer 2

high strength
corrosion resistance
stability
low creep
conductivity

Question 3

differentiate between amorphous solid structures and crystaline solid structures

Answer 3

crystalline atoms are arranged in a pattern

amorphous atoms are arranged randomly

Question 4

differentiate between solvus and solidus

Answer 4

a solvus line is the boundary between a solid solution solid and a eutectic alloy

a solidus line represents the end of solidification in an alloy

Question 5

differentiate between Body Centre Cubic (bcc) and Face Centre Cubic (fcc) structures

Answer 5

bcc structures are harder and more brittle

fcc are more ductile

Question 6

what does ductile mean?

Answer 6

flexible

able to be deformed without losing toughness