Foundry Metallurgy - Study Mode
[#21] In which of the following methods, close fitting cores are pushed in the cavities?
Correct Answer
(D) Pressed casting
[#22] Ferrous alloys are usually cast by . . . . . . . .
Correct Answer
(D) None of the above
Explanation
Solution: Ferrous alloys, such as cast iron and steel , have very high melting points compared to non-ferrous metals. Die casting machines, including hot and cold chamber types , are typically used for non-ferrous metals like aluminum, zinc, and magnesium, which have relatively low melting points. Hot chamber machines are not suitable for ferrous alloys because the molten metal would corrode or damage the injection components. Cold chamber machines are also unsuitable due to similar issues with extreme temperatures and wear. Ferrous alloys are usually cast using sand casting, investment casting, or shell molding , which can withstand the high temperatures required. Therefore, none of the options listed are appropriate for casting ferrous alloys.
[#23] Draft allowance given to patterns is for
Correct Answer
(B) easy removal of pattern from the mould cavity
[#24] For casting a cylindrical aluminum bloom having a length of 1000 mm and diameter of 700 mm. the approximate solidification time (in minutes) estimated using Chvorinov's rule is
Correct Answer
(D) 620
[#25] The shrinkage allowance for zinc is . . . . . . . . mm.
Correct Answer
(B) 24