Transcript Review

Metal and Non-metal Use in Automobiles
Figure I.1 Some of the metallic and nonmetallic materials used in a typical automobile
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Permanent Deformation
Figure 1.5 Permanent deformation (also called plastic deformation) of a
single crystal subjected to a shear stress: (a) structure before
deformation; and (b) permanent deformation by slip. The b/a ratio
influences the magnitude of the shear stress required to cause slip.
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Defects in a Single-Crystal Lattice
Figure 1.8 Schematic illustration of types of defects in a single-crystal lattice:
self-interstitial, vacancy, interstitial, and substitutional
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Edge Dislocation Movement
Figure 1.10 Movement of an edge dislocation across the crystal
lattice under a shear stress. Dislocations help explain why the actual
strength of metals is much lower than that predicted by theory.
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?
Solidification of Molten Metal
Figure 1.11 Schematic illustration of the stages during solidification of molten
metal; each small square represents a unit cell. (a) Nucleation of crystals at
random sites in the molten metal; note that the crystallographic orientation of
each site is different. (b) and (c) Growth of crystals as solidification continues.
(d) Solidified metal, showing individual grains and grain boundaries; note the
different angles at which neighboring grains meet each other.
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Recovery, Recrystallization, and Grain Growth Effects
Figure 1.14 Schematic illustration
of the effects of recovery,
recrystallization, and grain growth
on mechanical properties and on
the shape and size of grains. Note
the formation of small new grains
during recrystallization.
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Relative Mechanical Properties of Materials
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Loading and Unloading of Tensile-test Specimen
Figure 2.3 Schematic illustration
of the loading and the unloading
of a tensile-test specimen. Note
that, during unloading, the curve
follows a path parallel to the
original elastic slope.
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Power Law Constitutive Model
  K n
where

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K = strength coefficient
n = strain hardening
exponent
Temperature Effects on Stress-strain Curves
Figure 2.7 Typical effects of temperature on stress-strain curves. Note that
temperature affects the modulus of elasticity, the yield stress, the ultimate tensile
strength, and the toughness (area under the curve) of materials.
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Effect of Strain Rate on Tensile Strength of Al
Figure 2.8 The effect of strain
rate on the ultimate tensile
strength for aluminum. Note
that, as the temperature
increases, the slopes of the
curves increase; thus, strength
becomes more and more
sensitive to strain rate as
temperature increases.
Source: After J.H. Holloman
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Cooling of Metals
Figure 4.4 (a) Cooling curve for the solidification of pure metals. Note that freezing
takes place at a constant temperature; during freezing, the latent heat of
solidification is given off. (b) Change in density during the cooling of pure metals.
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Iron-iron Carbide Phase Diagram
Figure 4.8 The iron-iron carbide phase diagram. Because of
the importance of steel as an engineering material, this
diagram is one of the most important of all phase diagrams.
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Effect of Time and Temperature on Yield Stress
Figure 4.22 The effect of aging time and temperature on the yield
stress of 2014-T4 aluminum alloy. Note that, for each
temperature, there is an optimal aging time for maximum strength.
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Outline of Heat Treatment Processes for Surface Hardening
Mechanical Properties of Steel as a Function of
Tempering Temperature
Figure 4.25 Mechanical
properties of oilquenched 4340 steel as
a function of tempering
temperature.
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Cost of Wrought Metals and Plastics vs. Carbon Steel
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What happens to plastics as you move
from condition(a)
to (d)?Chains
Polymer
Figure 7.5 Schematic illustration of polymer chains. (a) Linear structure – thermoplastics
such as acrylics, nylons, polyethylene, and polyvinyl chloride have linear structures. (b)
Branched structure, such as in polyethylene. (c) Cross-linked structure – many rubbers or
elastomers have this structure, and the vulcanization of rubber produces this structure. (d)
Network structure, which is basically highly cross-linked – examples are thermosetting
plastics, such as expoxies and phenolics.
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Polymers become stronger and less
ductile with more cross linking.
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Ceramic Types and Characteristics
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Boeing 757-200
Figure 9.1 Application of advanced composite materials in Boeing 757-200 commercial aircraft.
Source: Courtesy of Boeing Commercial Airplane Company.
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Metal-Matrix Composite Materials and Applications
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Casting Design and Fluidity Test
Figure 10.8 Schematic illustration of a typical
riser-gated casting. Risers serve as reservoirs,
supplying molten metal to the casting as it
shrinks during solidification.
Figure 10.9 A test method for
fluidity using a spiral mold. The
fluidity index is the length of the
solidified metal in the spiral
passage. The greater the length
of the solidified metal, the greater
is its fluidity.
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Alloy Solidification
Figure 10.4 Schematic illustration of alloy solidification and temperature distribution in the
solidifying metal. Note the formation of dendrites in the mushy zone.
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Solidification Contraction or Expansion
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Expendable-Pattern Casting Process
Figure 11.11 Schematic illustration of the expendable-pattern casting process, also
known as lost-foam or evaporative casting.
Investment Casting Process
Figure 11.13 Schematic illustration of investment casting (lost-wax) process. Castings
by this method can be made with very fine detail and from a variety of metals. Source:
Courtesy of Steel Founder’s Society of America.
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Effects of Hot Rolling
Figure 13.6 Changes in the grain structure of cast or of large-grain wrought
metals during hot rolling. Hot rolling is an effective way to reduce grain size
in metals for improved strength and ductility. Cast structures of ingots or
continuous castings are converted to a wrought structure by hot working.
Shape Rolling of an H-section part
Figure 13.12 Steps in the
shape rolling of an Hsection part. Various other
structural sections, such as
channels and I-beams, also
are rolled by this kind of
process.
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Forged Components
Figure 14.1 (a) Schematic illustration of the steps involved in forging a knife. (b) Landinggear components for the C5A and C5B transport aircraft, made by forging. (c) General view
of a 445 MN (50,000 ton) hydraulic press. Source: (a) Courtesy of the Mundial LLC. (b and
c) Courtesy of Wyman-Gordon Company.
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Microstructure as a Function of Manufacturing
Method
Figure 14.2 Schematic illustration of a part made by three different processes showing grain
flow. (a) Casting by the processes described in Chapter 11. (b) Machining form a blank,
described in Part IV of this book, and (c) forging. Each process has its own advantages and
limitations regarding external and internal characteristics, material properties, dimensional
accuracy, surface finish, and the economics of production. Source: Courtesy of Forging
Industry Association.
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Extrusions and Products Made from Extrusions
Figure 15.2 Extrusions and
examples of products made by
sectioning off extrusions.
Source: Courtesy of Kaiser
Aluminum.
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Extrusion Temperature Ranges
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Process Variables in Wire Drawing
Figure 15.18 Process variables in wire drawing. The die angle, the reduction in crosssectional area per pass, the speed of drawing, the temperature, and the lubrication all affect
the drawing force, F.
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Characteristics of Sheet-Metal Forming Processes
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Deformation and Tearing in Sheet Metal During Forming
Figure 16.15 The deformation of the grid pattern and the tearing of sheet metal during
forming. The major and minor axes of the circles are used to determine the coordinates
on the forming-limit diagram in Fig. 16.14b. Source: After S. P. Keeler.
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Springback in Bending
3
Ri
R Y 
R Y 
 4 i
 3 i
 1




Rf
ET
ET

Figure 16.19 Springback in bending. The part tends to recover elastically after bending,
and its bend radius becomes larger. Under certain conditions, it is possible for the final
bend angle to be smaller than the original angle (negative springback).
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Parts Made by Powder-Metallurgy
(b)
(c)
(a)
Figure 17.1 (a) Examples of typical parts made by powder-metallurgy processes. (b) Upper
trip lever for a commercial sprinkler made by P/M. This part is made of an unleaded brass
alloy; it replaces a die-cast part with a 60% savings. (c) Main-bearing metal-powder caps for
3.8 and 3.1 liter General Motors automotive engines. Source: (a) and (b) Reproduced with
permission from Success Stories on P/M Parts, 1998. Metal Powder Industries Federation,
Princeton, New Jersey, 1998. (c) Courtesy of Zenith Sintered Products, Inc., Milwaukee,
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Density as a Function of
Pressure and the Effects of
Density on Other Properties
Figure 17.10 (a) Density of copper- and ironpowder compacts as a function of compacting
pressure. Density greatly influences the
mechanical and physical properties of P/M
parts. (b) Effect of density on tensile strength,
elongation, and electrical conductivity of
copper powder. Source: (a) After F. V. Lenel,
(b) IACS: International Annealed Copper
Standard (for electrical conductivity).
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Sintering Time and Temperature for Metals
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Comparison of Properties of Wrought and Equivalent P/M Metals
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Extruder Schematic
Figure 19.2 (a) Schematic illustration of a typical screw extruder. (b) Geometry of an
extruder screw. Complex shapes can be extruded with relatively simple and inexpensive dies.
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Production of Plastic Film and Bags
(b)
Figure 19.5 (a) Schematic illustration of the production of thin film and plastic bags from
tube – first produced by an extruder and then blown by air. (b) A blown-film operation. This
process is well developed, producing inexpensive and very large quantities of plastic film and
shopping bags. Source: Courtesy of Windmoeller & Hoelscher.
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Parts Made by Rapid-Prototyping
(c)
(a)
(b)
Figure 20.1 Examples of parts made by rapid-prototyping processes: (a) selection of
parts from fused-deposition modeling; (b) stereolithography model of cellular phone; and
(c) selection of parts form three-dimensional printing. Source: Courtesy of Stratasys, Inc.,
(b) and (c) Courtesy of 3D Systems, Inc.
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Fused-Deposition-Modeling
Figure 20.3 (a) Schematic illustration of the fused-deposition-modeling process. (b) The
FDM 5000, a fused-deposition-modeling machine. Source: Courtesy of Stratysis, Inc.
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Common Machining Operations
Figure 21.1 Some examples of common machining operations.
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Two-Dimensional
Cutting Process
Figure 21.3 Schematic illustration of a
two-dimensional cutting process, also
called orthogonal cutting: (a)
Orthogonal cutting with a well-defined
shear plane, also known as the
Merchant Model. Note that the tool
shape, depth of cut, to, and the cutting
speed, V, are all independent
variables, (b) Orthogonal cutting
without a well-defined shear plane.
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Tool-life Curves
Figure 21.17 Tool-life curves for a
variety of cutting-tool materials.
The negative inverse of the slope
of these curves is the exponent n
in the Taylor tool-life equation and
C is the cutting speed at T = 1
min, ranging from about 200 to
10,000 ft./min in this figure.
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Feed Marks on a Turned Surface
Surface roughness:
f2
Ra 
8R
where
f  feed
R  tool - nose radius

Figure 21.23 Schematic illustration of feed
marks on a surface being turned (exaggerated).
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Hardness of Cutting
Tool Materials as a
Function of
Temperature
Figure 22.1 The hardness of
various cutting-tool materials as a
function of temperature (hot
hardness). The wide range in
each group of materials is due to
the variety of tool compositions
and treatments available for that
group.
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General Properties of Tool Materials
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Inserts and Toolholders
Figure 22.2 Typical carbide inserts with various shapes and
chip-breaker features: Round inserts are also available, as
can be seen in Figs. 22.3c and 22.4. The holes in the inserts
are standardized for interchangeability in toolholders.
Source: Courtesy of Kyocera Engineered Ceramics, Inc.
Figure 22.3 Methods of mounting
inserts on toolholders: (a) clamping
and (b) wing lockpins. (c) Examples of
inserts mounted with threadless
lockpins, which are secured with side
screws. Source: Courtesy of Valenite.
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General Recommendations for Turning Operations
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Range of Surface
Roughnesses in
Machining
Processes
Figure 23.13 The range of
surface roughnesses obtained
in various machining
processes. Note the wide
range within each group,
especially in turning and boring.
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Range of
Dimensional
Tolerances in
Machining as a
Function of
Workpiece Size
Figure 23.14 Range of
dimensional tolerances obtained
in various machining processes
as a function of workpiece size.
Note that there is an order os
magnitude difference between
small and large workpieces.
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Milling Cutters and Milling Operations
Figure 24.2 Some basic types of milling cutters and milling operations. (a) Peripheral milling. (b) Face
milling. (c) End milling. (d) Ball-end mill with indexable coated-carbide inserts machining a cavity in a
die block. (e) Milling a sculptured surface with an end mill, using a five-axis numerical control machine.
Source: (d) Courtesy of Iscar. (e) Courtesy of The Ingersoll Milling Machine Co.
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Summary of Peripheral Milling Parameters and
Formulas
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Face-Milling Cutter
Figure 24.7 Terminology for a face-milling cutter.
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Horizontal-Spindle Machining Center
Figure 25.2 A horizontal-spindle machining center equipped with an automatic tool
changer. Tool magazines can store up to 200 cutting tools of various functions and
sizes. Source: Courtesy of Cincinnati Milacron, Inc.
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Machining Centers
Figure 25.4 (a) Schematic illustration of the top view of a horizontal-spindle machining
center showing the pallet pool, set-up station for a pallet, pallet carrier, and an active
pallet in operation (shown directly below the spindle of the machine). (b) Schematic
illustration of two machining centers with a common pallet pool. Various other pallet
arrangements are possible in such systems. Source: Courtesy of Hitachi Seiki Co., Ltd.
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Chatter Marks on Surface of Turned Part
Figure 25.13 Chatter marks (right of center of photograph) on surface of a turned part.
Source: Courtesy of General Electric Company.
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Bonded Abrasives Used in Abrasive-Machining Processes
Figure 25.1 A variety of bonded abrasives used in abrasivemachining processes. Source: Courtesy of Norton Company.
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Chemical Milling
Figure 27.2 (a) Missile skin-panel section contoured by chemical milling to improve the
stiffness-to-weight ratio of the part. (b) Weight reduction of space-launch vehicles by the
chemical milling of aluminum-alloy plates. These panels are chemically milled after the
plates first have been formed into shape by a process such as roll forming or stretch forming.
The design of the chemically machined rib patterns can be modified readily at minimal cost.
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Stepped Cavities Produced by EDM Process
Figure 27.11 Stepped cavities produced with a square electrode by the EDM
process. The workpiece moves in the two principle horizontal directions (x – y), and
its motion is synchronized with the downward movement of the electrode to produce
these cavities. Also shown is a round electrode capable of producing round or
elliptical cavities. Source: Courtesy of AGIE USA Ltd.
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Nonmetallic Parts Made by Water-Jet Cutting
Enlargement of Fig. 27.16c. Examples of various nonmetallic parts produced by
the water-jet cutting process. Source: Courtesy of Possis Corporation
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Fabrication of
Integrated Circuits
Figure 28.2 Outline of the general
fabrication sequence for integrated
circuits.
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Circuit Board Structures and Features
Figure 28.29 Printed circuit board structures and design features.
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Example: Surface Micromachining of a Hinge
(a)
(b)
Figure 29.6 (a) SEM image of a deployed micromirror. (b) Detail of the micromirror
hinge. Source: Courtesy of Sandia National Laboratories.
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Fusion Welding Processes
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Weld Bead Comparison
(a)
(b)
Figure 30.14 Comparison of the size of weld beads: (a) laser-beam or electronbeam welding, and (b) tungsten-arc welding. Source: American Welding Society,
Welding Handbook (8th ed.), 1991.
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Ultrasonic Welding
Figure 31.2 (a) Components of an ultrasonic welding machine for making lap welds. The lateral
vibrations of the tool tip cause plastic deformation and bonding at the interface of the
workpieces. (b) Ultrasonic seam welding using a roller as the sonotrode.
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Friction Stir Welding
Figure 31.5 The principle of the friction stir welding process. Alluminum-alloy plates
up to 75 mm (3 in.) thick have been welded by this process.
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