Roll No.

SHAMBHUNATH INSTITUTE OF ENGINEERING AND TECHNOLOGY

Subject Code KME 403 Subject: Manufacturing Processes
B.Tech: II Yr SEMESTER: IV
FIRST SESSIONAL EXAMINATION, EVEN SEMESTER, (2019-2020)
Branch: Mechanical Engineering
Solution
Time –1hr 30 min Maximum Marks – 30

SECTION – A

1. Attempt all questions in brief. (1*5 = 5)

QN QUESTION Marks CO BL
How metal forming processes are classified?
Ans: i) Casting, foundary or moulding processes
a. 1 1 1
ii) Forming or metal working
iii) Machining processes
Define elastic and plastic deformation.
Ans:

b. 1 1 2

Name different types of casting defects.

Ans: 1. Pinholes
2. Subsurface blowhole
3. Run out
c. 4. Swells 1 1 1

5. Drops
6. Metal penetration
7. Shift/mismatch

d. Write different defects of deep drawing. 1 1 1

 1. Earing
2. Bulging
3. Buckling
4. Scratch
Explain hand forging.
Ans: Hand Forging. Hand forging is also known as blacksmithing and is the
e. simplest form of forging. The metal which is to be forged is firstly heated to red 1 1 2
heat in the fire of a forge. It is then beaten into the wanted shape on a metal anvil
with hammers.

SECTION - B
2. Attempt any TWO of the following: (2*5 = 10)
QN QUESTION Marks CO BL
Differentiate between hot working and cold working.
Ans:

a. 5 1 2

What do you understand by yield criteria for ductile materials? Find out the
b. relation between Von Mises and Tresca’s yield criteria. 5 1 4
Ans:
 Discuss the role of casting volume and surface area as they relate to the total
solidification time.
Ans:

c. 5 1 4

What do you understand by powder metallurgy process? Explain atomization

d. 5 1 2
process of powder production.
 Ans: BASIC PROCESSES OF POWDER METALLURGY.
The basic operation of powder metallurgy techniques
• The four basic operations of the powder metallurgy are:
1. Manufacture of powder
2. Mixing or blending powder particles.
3. Compacting.
4. Sintering.
Atomization is accomplished by forcing a molten metal stream through an orifice at
moderate pressures. A gas is introduced into the metal stream just before it leaves
the nozzle, serving to create turbulence as the entrained gas expands (due to
heating) and exits into a large collection volume exterior to the orifice. The collection
volume is filled with gas to promote further turbulence of the molten metal jet. Air and
powder streams are segregated using gravity or cyclonic separation. Most atomized
powders are annealed, which helps reduce the oxide and carbon content. The water
atomized particles are smaller, cleaner, and nonporous and have a greater breadth of
size, which allows better compacting. The particles produced through this method are
normally of spherical or pear shape. Usually, they also carry a layer of oxide over
them.
There are three types of atomization:

 Liquid atomization
 Gas atomization
 Centrifugal atomization

SECTION - C

3. Attempt any ONE part of the following: (1*5 = 5)

Q QUESTION Mar C B
ks O L
N
How does a compound die differs from a progressive die? Giving a neat sketch describe
constructional features.
Ans: Dies and its Types:

Die:
The die may be defined as the female part of a complete tool for producing work in a press. It
is also referred to a complete tool consists of a pair of mating members for producing work in
a press.
Types of dies:
The dies may be classified according to the type of press operation and according to the
a method of operation.
5 1 4
. (A) According to type of press operation:
According to this criterion, the dies may be classified as cutting dies and forming dies.
1: Cutting Dies:
These dies are used to cut the metal. They utilize the cutting or shearing action. The common
cutting dies are: blanking dies, perforating dies , notching dies , trimming , shaving and
nibbling dies.
2: Forming Dies:
These dies change the appearance of the blank without removing any stock. Theses dies
include bending, drawing and squeezing dies etc.
(B) According to the method of operation:
According to this criterion, the dies may be classified as : single operation or simple dies ,
compound dies , combination dies , progressive dies , transfer dies and multiple dies.
1: Simple Dies:
Simple dies or single action dies perform single operation for each stroke of the press slide.
The operation may be one of the operation listed under cutting or forming dies.
2: Compound Dies:
In these dies, two or more operations may be performed at one station. Such dies are
considered as cutting tools since, only cutting operations are carried out. Figure shows a
simple compound die in which a washer is made by one stroke of the press. The washer is
produced by simulation blanking and piercing operations. Compound dies are more accurate
and economical in production as compared to single operation dies.

3: Combination Dies:
In this die also , more than one operation may be performed at one station. It is difficult from
compound die in that in this die, a cutting operation is combined with a bending or drawing
operation, due to that it is called combination die.

4: Progressive Dies:
A progressive or follow on die has a series of operations. At each station , an operation is
performed on a work piece during a stroke of the press. Between stroke the piece in the metal
strip is transferred to the next station. A finished work piece is made at each stroke of the
press. While the piercing punch cuts a hole in the stroke , the blanking punch blanks out a
portion of the metal in which a hole had been pierced at a previous station. Thus after the first
stroke , when only a hole will be punched , each stroke of the press produces a finished
washer.
 What is a role of clearance in blanking and piercing operations? How clearance is provided on
punch and die?
Ans:

b
5 1 3
.
4. Attempt any ONE part of the following: (1*5 = 5)
Q QUESTION Mark C B
N s O L
A hole of 100 mm is to be punched in a cold rolled medium carbon steel plate of 5.6 mm
thickness. The ultimate shear strength of plate material is 550 MPa. With normal clearance
of 10% on the press tool, cutting is completed at 40% penetration of the punch. Calculate
the die for the punch and die required for the purpose. If the shop has press of 30 tonnes
capacity. Calculate the shear angle to be provided on the punch in order to bring the work
within the capacity of the existing press.
Ans: Clearance per side = 10% of plate thickness
= 0.56 mm
Punch Dia= hole dia =100mm

a. 5 1 3
 Show that during deep drawing of a cup, the radial stresses σr at radius r is given by

Where,
Fh is the blank holding force, rj is the initial blank radius, t is the thickness and µ is
coefficient of friction, K is the shear yield strength.
Ans:

b
5 1 5
.
5. Attempt any ONE part of the following: (1*5 = 5)
Q QUESTION Mark C B
N s O L
For an ease of molding, it is decided to replace a spherical riser of dia 100 mm by a
cylindrical riser. Determine the size of the cylindrical riser that will have the identical
solidification time. Ratio of height to radius of cylinder is 2:1.
Ans:

a. 5 1 3

b Drive the following expression for pressure distributions (for sliding friction) for forging of 5 1 5
. a rectangular block (b x h x w) and show the variation

where p is the pressure at a distance x from center, K is shear strength of material and µ is
the coefficient of sliding friction, h is the height and b the width.
Ans: