GTU BE 6th Semester 2162103 Powder Metallurgy Summer 2018 Question Paper

1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE – SEMESTER ?VI (NEW) – EXAMINATION ? SUMMER 2018
Subject Code:2162103 Date:28/04/2018
Subject Name:Powder Metallurgy
Time:10:30 AM to 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) List the basic steps in the P/M technique. 03
(b) How many ways one can produces metal powder production? 04
(c) What are the advantages and limitations of Powder Metallurgy? 07

Q.2 (a)Micro-hardness of sinter compact dependences on porosity ?Justify the statement.
03
(b)The main factor for altering the apparent density is not the particle size but particle
size distribution. ?Justify statement.
04
(c) What do you mean by characterization of metal powders? Discuss the tool(s)& techniques used for the characterization of metal powders with respect to
their purity, shape, size and green strength.
07
OR
(c) Define flow rate of powders. How it is to be measured? 07
Q.3 (a) Explain the term: (i) Tap Density (ii) Flowability (iii) Apparent Density 03
(b) Why apparent density so important in P/M? 04
(c) How do you determine particle size distribution by Sieve Analysis? Give the
ASTM standard for such measurement.
07
OR
Q.3 (a) What is the atomization process for manufacturing of metal powder? Draw
neat sketch to show this process.
03
(b) Illustrate with figure the mechanism of atomization. 04
(c) How do you distinguish between gas and water atomization? Briefly Explain. 07
Q.4 (a) What do you mean by compatibility and green density? 03
(b) What are the steps involved in powder rolling to manufacture the sheet? 04
(c) By which technique the difficulty in conventional die compaction can be
overcome? Explain it Briefly.
07
OR
Q.4 (a) What do you mean by blending and mixing of powder? 03
(b) Classify powder compaction methods with and without pressure. 04
(c) Explain pyrophoricity and toxicity of powders. 07
Q.5 (a) What is slip in slip casting method? 03
(b) Explain with figure double die compaction method. 04
(c) What is the effect of type of compaction on green density distribution?
Explain with figure.
07
OR
Q.5 (a) What is the purpose of Sintering in P/M? 03
(b) Explain solid state sintering briefly. 04
(c) With schematic diagram of progress of sintering. Explain in detail liquid
phase sintering.
07
*************