Aluminum Alloys

Question 1

What is the name of Aluminum ore?

Answer 1

Bauxite

Question 2

What are the 2 steps of retrieving Aluminum?

Answer 2

1) Bayer process: using caustic leaching Al2O3 is produced, a white powder when fluids are evaporated

2) Hall Heroult process: electrometallurgy separates Al and Oxygen.

Question 3

What are the advantages of Aluminum?

Answer 3

1) Light, a third density of steel
2) Good thermal/electric conductor
3) High strength to weight ratio
4) Tensile strength increases as the temperature decreases
5) Weldable
6) Good corrosion resistance
7) Non-magnetic
8) Good formability
9) Non-toxic

Question 4

How is Aluminum designated?

Answer 4

1st digit: alloying element
2nd digit: indicates whether the alloy is modified
last 2 digits: identifiers

eg. if 2017 is a high Cu alloy the 2024 is another high Cu alloy. 2224 is a modification of the 2024 Cu alloy

Question 5

Above what temperature should Aluminum be heat treated?

Answer 5

Above 515 deg C

Question 6

What does quenching do to Aluminum?

Answer 6

Forms a supersaturated unstable solid solution

Question 7

What are the 2 kinds of aging?

Answer 7

1) Natural: aging at room temperature that lets the second phase precipitate out

2) Artificial: aging at elevated temperatures to optimize strength. This allows the secondary phase to precipitate out quicker.