Metallurgy Test Quiz | Metallurgy Test Objective Type Questions & Answers

Questions
21 At room temperature, hardness of precipitation hardening alloys ______
A increases with time
B decreases with time
C remains constant
D none of the above

Answer: increases with time
22 In precipitation hardening, at 540o C when θ phase (CuAl2) completely dissolves at grain boundaries the single phase α is obtained known as ____
A saturated solid solution
B homogeneous solid solution
C heterogeneous solid solution
D supersaturated solid solution

Answer: homogeneous solid solution
23 What is the composition of cartridge brass?
A 50 % Cu and 50 % Zn
B 60 % Cu and 40 % Zn
C 70 % Cu and 30 % Zn
D 20 % Cu and 80 % Zn

Answer: 70 % Cu and 30 % Zn
24 In Muntz metal, if 1% of tin is added it forms _____
A admiralty brass
B naval brass
C both a. and b.
D none of the above

Answer: naval brass
25 Which of the following is α – β brass?
A Admiralty brass
B Brazing brass
C Cartridge brass
D All of the above

Answer: Brazing brass
26 Which of the following parameters is/are false for steel?
A High carbon content
B High melting point
C Low damping capacity
D None of the above

Answer: High carbon content
27 Nodules of graphite are observed in the microstructure of _______
A white cast iron
B malleable cast iron
C spheroidal cast iron
D all of the above

Answer: spheroidal cast iron
28 What is the effect of silicon on the structure of cast iron?

1. Blowholes are present in the castings

2. Increases fluidity

3. Influences the solidification of liquid alloys

4. Reacts with iron to form iron sulphide

A 1 and 2
B 2 and 3
C 3 and 4
D All of the above

Answer: 2 and 3
29 In mottled cast iron, slow cooling rate is used to obtain ______
A white cast iron
B gray cast iron
C Both a. and b.
D None of the above

Answer: gray cast iron
30 The gray cast iron has ____
A high melting point
B high thermal conductivity
C low compressive strength
D all of the above

Answer: high thermal conductivity
junior administrative assistant jaa test series