Engineering Materials - Study Mode

[#66] Malleable cast iron
Correct Answer

(C) Is produced by annealing process. It is soft, tough and easily machined metal

Explanation

Solution: Malleable iron is cast as white iron, the structure being a metastable carbide in a pearlitic matrix. Through an annealing heat treatment, the brittle structure as first cast is transformed into the malleable form.

[#67] Bell metal contains
Correct Answer

(D) 70 - 75% copper and rest tin

Explanation

Solution: Bell metal contains 70 - 75% copper and rest tin

[#68] Which is false statement about normalizing? Normalizing is done to
Correct Answer

(D) Induce stresses

Explanation

Solution: Normalizing is normally done to achieve any one of the following purposes. To modify and/or refine the grain structure and to eliminate coarse grained structures obtained in previous working operations such as rolling and forging.

[#69] Chilled cast iron has
Correct Answer

(A) No graphite

Explanation

Solution: Chilled cast iron. Iron-carbon alloy with low graphitization factor so that chill occurs forming a graphite-free structure. The carbon is present bonded in the form of iron carbide, which is why the break surface of the material appears whitish instead of gray.

[#70] The aluminium alloy, mainly used, for anodized utensil manufacture, is
Correct Answer

(D) Hindalium

Explanation

Solution: cooking vessels made of aluminium or hindalium for cooking food. Even if a steel spoon is brushed with force against aluminium vessels, minute particles of aluminium will appear as residue. Hindalium is Alloy of aluminium magnesium, manganese, chromium and silicon.