Sheet Metal Forming Processes
Ratio Surface Area:Volume is very high for
sheet metal process.
Plates thickness > 0.25 inches
Boilers, bridges, ships, etc. use relatively thick plates
Usually sheet forming is done on relatively thin
MAE 364: Manufacturing Processes
HOME WORK 4 (Spring 2013)
Due Date: Friday, March 29, 2013
1) Explain why there are so many different kinds of forging machines available.
Depending on the end product, different forging operations (coining, heading, pierc
MAE 364: Manufacturing Processes
Home work 6 - Solution
Total Points: 100
1. Explain why the cutting force, Fc , increases with increasing depth of cut and decreasing rake
(a) Increasing the depth of cut means more material being removed per unit t
Is the machining technology used to make microscale (0.000001 meter = 1 micron) devices
Micro-devices are used currently in systems ranging
from our cell phones to rockets
What do they look like?
Chapter 3 in the text book
Introduction of molten metal into a mold cavity where the metal
confirms to the shape of the cavity
Intricate shapes in a single piece
Very small and hollow parts can be produced
Inportant factors of deep drawing
Properties of the sheet
ratio of blank dia and punch dia
punch and die corner radii
speed of punch
holding force etc
Limiting drawing ratio (LDR)
Max D0/Dp ratio
R (normal anisot
Punch and die
Ratio of rough area:burnished area increases
with higher ductility
Punch travel depends on the ductility or
A brittle metal requires little travel.
Punch Force = shear strength * crosssectional
Bending of Sheet and Plate
Bending is done to form flanges, etc.
Also for giving stiffness to a sheet part
Length of neutral axis
l0 ( R T )
l f ( R T )
l f l0 l f
( R T )
( R T / 2) 2 R
In bending outer fibers are in tensi
Mechanics of Chip Formation
How can we calculate:
Chip thickness tc
Depth of cut t0
r is called chip thickness ratio.
1/r is called c
Week 3 Recitation Questions Casting
1) Determine the amount of gamma and alpha phases in a 10-kg, 1040 steel casting as it is being
cooled slowly to the following temperatures: (a) 900oC, (b) 728oC, (c) 726oC.
a) For 0.40% C at 900oC we are in the single-
MAE364 Recitation - Week 6 Review of Mechanical Behavior of Materials
Material behavior is very important for the next topic of Bulk Deformation.
Engineering Stress & Strain
FIGURE 2.2 (a) Original and final shape of a standard tensile-test specimen. (b)
MAE364 Recitations - Week 9 Sheet metal
The approximate formula to estimate springback is:
is the uniaxial yield stress of the material.
Deep drawability Determining the limiting drawing rati
MAE364 Recitation Week 8 Extrusion & Drawing
Extrusion: material (in the form of a billet) is forced through a die by a ram. Process is ideal for creating
parts with a constant cross-section.
Parameters describing the extrusion process:
Extrusion Ratio, :
MAE364 Recitation Week 11 Material removal
Material removal rate (MRR) the volume of material removed per unit time.
Power required for machining (use specific energy from Table 3):
MAE364 Recitation Week 8 Rolling & Drawing
Roll forces (for low friction conditions):
Power per roller (in kW):
Power per roll (in hp):
Drawing: Maximum reduction of area per pass
for plane strain.
Problem 1: A 9-in.-wid
MAE364 Recitation - Week 6 Bulk Deformation
Work of Deformation: (From pages 70-72)
A quantity equivalent to work per unit volume is the product of stress and strain.
The area under the true stress-strain curve for any strain is the energy per unit volume
Week 4 Recitation Welding
1) A shielded metal arc welding operation takes place on a steel workpiece (with a steel electrode)
with a 20-volt power supply. If a weld with a triangular cross section with a 10-mm leg length is
to be produced, estimate the cu