This set of Casting, Forming and Welding Multiple Choice Questions & Answers (MCQs) focuses on “Aluminium and Its Alloys”.
1. Presence of which material in aluminium alloy provides ductility to the alloy?
Explanation: With the presence of about 2% to 5% of copper metal in aluminium alloy aids in the increase in ductility of the alloy, that is, it becomes easy for the alloy to be stretched into wires.
2. Which furnace is not used for heating aluminium alloys?
a) Electric arc furnace
b) Pot furnace
c) Induction heating furnace
d) Crucible furnace
Explanation: Aluminium alloys can be melted or heated directly or indirectly by fuel firing furnace. The heating can take place in a pot furnace, induction heating furnace, a crucible furnace or a reverberatory furnace.
3. Which of the following is not a purpose of fluxing and flushing the aluminium alloys?
a) Removal of dissolved hydrogen
b) Removal of dissolved oxygen
c) Separation of dross from melt
d) Entrapment of dross
Explanation: Fluxing and flushing are an important task in aluminium alloy foundries. It is done for removing the dissolved hydrogen from the melt, for separating the dross from molten metal and to entrap the dross.
4. What is the silicon composition present in an LM-17 cast aluminium alloy?
Explanation: In an LM-1 cast aluminium alloy, silicon content is 3%. In an LM-13 cast aluminium alloy, silicon content is 12%. In an LM-8 cast aluminium alloy, silicon content is 5.5% and in an LM-17 cast aluminium alloy, the silicon content is 11.5%.
5. Which gas is not used for fluxing and flushing in aluminium alloys?
Explanation: Fluxing and flushing is an operation which is done for the removal of hydrogen from the molten metal. In this process, argon gas, chlorine gas, nitrogen gas and helium gas are used as fluxes and not oxygen.
6. Up to what length can the surface finish be achieved by green sand in aluminium alloys?
a) 600 micro inch
b) 650 micro inch
c) 700 micro inch
d) 750 micro inch
Explanation: When green sand is used for molding in aluminium alloys, the surface finish can be achieved from about 300 micro inch to 650 micro inch, which is about 7500 micro mm to 16,250 micro mm.
7. Which of the given metals is not counted among late additions in aluminium alloys?
Explanation: There are certain metals which are added very late in the molten cast. By doing this, aluminium alloys get refined. A few of those metals are, boron, titanium, sodium, chromium and columbium. Manganese is added in aluminium during the operation, not late.
8. Aluminium alloys are not susceptible to which of the following?
a) Macro shrinkage
c) Micro shrinkage
d) Solidification shrinkage
Explanation: Aluminium alloys are susceptible to drossing, micro shrinkages and solidification shrinkages, but not to macro shrinkages. For prevention of entering of dross in mold cavity, gating system is installed.
9. A runner is located away from the drag.
Explanation: A runner has to be located in the drag. The area of the runner should be small and ideally equal to the ingate area. It should be streamlined to avoid turbulence.
10. Pouring basins are used for reducing vortex formation.
Explanation: The design made for pouring basins in the working of aluminium alloys, is purposed for the reduction of turbulence and vortex formation. It also aids in the reduction of mechanical washing of dross.
Sanfoundry Global Education & Learning Series – Casting, Forming and Welding.
To practice all areas of Casting, Forming and Welding, here is complete set of 1000+ Multiple Choice Questions and Answers.