Powder Metallurgy MCQs : Here you will find MCQ Questions related to "basic" in Powder Metallurgy. These basic MCQ Questions Will help you to improve your Powder Metallurgy knowledge and will prepare you for various Examinations like Competitive Exams, Placements, Interviews and other Entrance Exmaniations
Question 1
___________is a term covering a wide range of ways in which materials or components are made from metal powders.
A. Powder metallurgy
B. Phase Transformation
C. Foundry
D. None of the above
View Answer
Ans : A
Explanation: Powder metallurgy (PM) is a term covering a wide range of ways in which materials or components are made from metal powders.
Question 2
PM processes can greatly the need to use metal removal processes
A. increase
B. reduce
C. remain same
D. Can not say
View Answer
Ans : B
Explanation: PM processes can avoid, or greatly reduce, the need to use metal removal processes, thereby drastically reducing yield losses in manufacture and often resulting in lower costs.
Question 3
The powder metallurgy press and sinter process generally consists of __________ basic steps
A. 1
B. 2
C. 3
D. 4
View Answer
Ans : C
Explanation: The powder metallurgy press and sinter process generally consists of three basic steps: powder blending (pulverisation), die compaction, and sintering.
Question 4
Which technologies rely on electric currents to densify powders?
A. ECAB
B. PCAS
C. DERS
D. ECAS
View Answer
Ans : D
Explanation: Electric current assisted sintering (ECAS) technologies rely on electric currents to densify powders, with the advantage of reducing production time dramatically (from 15 minutes of the slowest ECAS to a few microseconds of the fastest), not requiring a long furnace heat and allowing near theoretical densities but with the drawback of simple shapes.
Question 5
How many types of atomization there?
A. 2
B. 3
C. 4
D. 5
View Answer
Ans : B
Explanation: There are three types of atomization: Liquid atomization, Gas atomization, Centrifugal atomization
Question 6
Powder compaction is the process of compacting metal powder in a die through the application of high pressures
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
View Answer
Ans : A
Explanation: True, Powder compaction is the process of compacting metal powder in a die through the application of high pressures.
Question 7
Reynolds number R =?
A. (fvd)/(n*n)
B. fv/nd
C. vd/n
D. fvd/n
View Answer
Ans : D
Explanation: Simple atomization techniques are available in which liquid metal is forced through an orifice at a sufficiently high velocity to ensure turbulent flow. The usual performance index used is the Reynolds number R = fvd/n, where f = fluid density, v = velocity of the exit stream, d = diameter of the opening, and n = absolute viscosity.
Question 8
In Power compaction, The density of the compacted powder decreases with the amount of pressure applied?
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
View Answer
Ans : B
Explanation: The density of the compacted powder increases with the amount of pressure applied. Typical pressures range from 80 psi to 1000 psi (0.5 MPa to 7 MPa), pressures from 1000 psi to 1,000,000 psi have been obtained.
Question 9
Which of the following process gives a case with microstructure consisting of iron carbonitride and iron nitride?
A. Carbonitriding
B. Nitriding
C. Liquid-carburizing
D. Nitrocarburizing
View Answer
Ans : D
Explanation: In nitrocarburizing, the microstructure of the case (after quenching in oil) consists of a thin layer of iron carbonitride and iron nitride (white layer), with a diffused layer of iron nitride, alloy nitrides and nitrogen.
Question 10
_________ is done to reduce dimensional scatter as well as to obtain closure of surface pores
A. Machining
B. Plating
C. Repressing
D. Sizing
View Answer
Ans : C
Explanation: The primary aim of repressing is densification of the sintered part to give improved physical and mechanical properties along with dimensional tolerances. Thus, most of the P/M parts are repressed to reduce dimensional scatter as well as to obtain closure of surface pores.