Uses of aluminium
3 marks · EasyPure aluminium is not commonly used for building structures. The table below shows two metals and two alloys.
| Material | Type |
|---|---|
| Aluminium | Pure metal |
| Steel | Alloy |
| Duralumin | Alloy |
| Copper | Pure metal |
State why pure aluminium is rarely used instead of its alloys.
Explain how alloying aluminium changes its structure to make it stronger.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) Pure aluminium is not very strong.
(b) Alloying aluminium introduces atoms of different sizes, distorting the regular arrangement and making it more difficult for atoms to slide over each other. · must show Reference to different sized atoms disrupting the lattice, Explanation of prevention of movement of layers
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Marking points
B1 (a) · 1 mark · States that pure aluminium is not strong or not as strong as the alloy.
M1 (b) · 1 mark · Mentions different sized atoms or ions disrupt the lattice/structure.
M2 (b) · 1 mark · Explains that this makes it more difficult for layers/ions/atoms to slide over each other (increases strength).
Worked solution
a) Pure aluminium is rarely used because it is not very strong.
b) Alloying aluminium adds atoms of different sizes to the structure. These different sized atoms disrupt the regular layers of atoms, making it harder for the layers to slide over each other. This increases the strength of the material.