Uses of aluminium
3 marks · EasyThe table shows the strength of pure aluminium and some aluminium alloys.
| Material | Relative Strength |
|---|---|
| Pure aluminium | Low |
| Aluminium + magnesium | High |
| Aluminium + copper | Very high |
Which of the materials in the table would be least suitable for use in construction? Give a reason.
State how alloying with copper affects the strength of aluminium.
Explain why adding another metal to aluminium changes its strength.
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.
Show answer
(a) Pure aluminium; because it has low strength.
(b) It increases the strength of aluminium to very high.
(c) It makes the layers of atoms harder to slide, increasing strength. · must show Disrupts regular lattice, Prevents/easier sliding
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Identifies pure aluminium as least suitable and gives reason linked to low strength.
B2 (b) · 1 mark · States that alloying with copper increases strength (to very high).
B3 (c) · 1 mark · Explains that alloying disrupts atomic structure, preventing layers from sliding.
Worked solution
a) Pure aluminium is least suitable for construction because it has low strength.
b) Alloying with copper increases the strength of aluminium to very high.
c) Adding a metal like copper creates atoms of different sizes in the alloy, disrupting the regular arrangement and making it harder for layers to slide, thus increasing strength.