Question

Die casting of aluminium is not done because of the reason that, it is

• A. Prone to high expansion on solidification
• B. Having high tendency to react chemically with the die surface
• C. Strong and light weight
• D. Having high melting point and cooling time

Hint:

In casting processes, always consider the chemical compatibility between molten metal and die material to avoid reactions that degrade die surfaces or casting quality.

Answer 1

The Correct Option is B

Aluminium is generally avoided in traditional die casting processes because it has a strong tendency to react chemically with the steel die. This reaction forms an alloy at the die surface, leading to soldering or sticking of aluminium to the die, which affects the dimensional accuracy and surface finish of the casting and reduces die life. While aluminium is commonly used in pressure die casting with special coatings and lubricants, in conventional gravity die casting, this reactivity presents a significant drawback.