Chapter 6 Aluminium and its alloys

Question 1

Which of the following methods improve strength of pure aluminium?

1. Tempering
2. Hardening
3. Cold Working
4. Hot Forging

Answer 1

3. Cold Working

Question 2

The degrees of strength and hardness of non heat-treatable wrough aluminium alloys can be controlled by varying amount of cold working. These alloys are said to be of different…?

Answer 2

tempers

Question 3

Which of the following aluminium alloy is non-heat treatable?

1. 7xxxx
2. 6xxxx
3. 3xxxx
4. 2xxxx

Answer 3

3. 3xxxx

Question 4

What is the microstructure of slowly cooled duralumin?

Answer 4

Coarse Compound in αAl

Question 5

What is the microstructure of Solution Treated Condition?

Answer 5

Supersaturated Solid Solution of αAl

Question 6

What is the microstructure of aged hardened at 165 degrees C for 10 hours?

Answer 6

Fine Precipitate in αAl

Question 7

What is the mechanical property of slowly cooled duralumin?

Answer 7

Soft & Weak

Question 8

What is the mechanical property of Solution Treated Condition?

Answer 8

Very Ductile

Question 9

What is the mechanical property of aged hardened at 165 degrees C for 10 hours?

Answer 9

High Strength & Hardness

Question 10

After re-heating solution treated Duralumin at 165 degrees C for 30 hours, the microstructure consists of…?

1. 100% α phase
2. fine compound in α matrix
3. supersaturated solid solution
4. coarse compound in α matrix

Answer 10

4. coarse compound in α matrix