1. Aluminium alloys are used for constructing very few parts in an aircraft due to lack of availability.
a) True
b) False
Explanation: The above statement is incorrect. Aluminium alloys are materials with lots of advantages. They are used extensively in building an aircraft. The structure of the aircraft and wing beams are also manufactured using aluminium alloys.
2. The melting point of aluminium is ___________
a) 236°c
b) 1085°c
c) 660°c
d) 1510°c
Explanation: The melting point of aluminium is 660°c. Aluminium alloys are subjected to different temperatures during heat treatment. The melting point of copper is 1085°c. The melting point of steel is 1510°c.
3.Which of the following is not a common property for all aluminium alloys?
a) Low strength
b) Heat treatable
c) Easy for machining
d) Readily joined be welding
Explanation: Aluminium alloys are good materials to use in the aerospace industry. They are heat treatable, can readily be joined by welding, soldering and are easy to machine. They also have high strength.
4.Aluminium is __________
a) non-magnetic
b) ductile
c) magnetic
d) non-magnetic and ductile
Explanation: Aluminium is a soft material. It is silvery-white in colour. It has a melting point of around 660°c. It is also both non-magnetic and ductile in nature. The atomic number of the element aluminium is 13.
5. Which of the following is not an aluminium alloy?
a) Al-Si
b) Al-Zn
c) Al-Mn
d) Al-U
Explanation: Aluminium alloys are alloys where aluminium is present in a higher amount. Aluminium alloys can be made with aluminium and zinc, aluminium and manganese, aluminium and silicon, etc. Uranium is a radioactive material
6. Why has the aluminium association established a system of designating aluminium alloys?
a) To create employment
b) To remove confusion
c) To encourage research
d) To ensure availability
Explanation: The aluminium association has made this system to remove confusion. The confusion was caused due to companies having different numbering systems for aluminium materials of similar chemical composition.
7.The final two digits in the nomenclature of aluminium alloys represent aluminium __________
a) impurity
b) group
c) purity
d) strength
Explanation: The nomenclature of aluminium alloys was made by the aluminium association to avoid confusion. It consists of 4 digits that represent various parameters. The last two digits indicate aluminium purity.
8. Pitting of the surface is a kind of aluminium alloy __________
a) corrosion
b) annealing
c) strength
d) manufacturing method
Explanation: One of the most important factors to consider while dealing with materials is corrosion. Aluminium alloys can be painted with a coating to avoid it. Pitting of the surface is corrosion that affects the surface due to the existence of moisture
9. Aluminium alloys can be categorized into Cast and ___________ alloys.
a) extrusions
b) heat treatable
c) non-heat treatable
d) wrought
Explanation: Aluminium alloys are alloys where aluminium is present in a higher amount. It can be roughly categorized into two categories. Cast alloys and wrought alloys. Both the categories can again be divided into heat-treatable and non-heat treatable.
10. Aluminium alloys also have a system that indicates temper.
a) True
b) False
Explanation: Aluminium alloys have a system of designation that is denoted by four digits. The four digits are followed by the temper designation. It consists of the letters O, F, H and T after which there is a number. They represent annealed, fabricated and strain hardened respectively.