(a) List three qualities of commercial purity aluminium. (3 marks) (b) For each of the qualities listed in your answer to question 1. (a), list one application of aluminium that benefits directly from it. (3 marks) (c) Explain why alloying of aluminium is necessary for many engineering applications. (3 marks) (d) Write brief notes on each of the following two aluminium alloy families. In your answer make reference to typical alloy content, strengthening mechanisms, mechanical properties, weldability, corrosion resistance and typical applications. (i) Wrought Al-Mg (5xxx) series alloys; and Wrought Al-Mg-Si (6xxx) series alloys. (8 marks) (8 marks)