Welding

Weld Joints

(a) Butt joint

(b) Corner joint

(c) T joint

(d) Lap joint

(e) Edge joint

FIGURE 12.1 Examples of welded joints.

     h     t    g    n    e    r     t S

   y     t     i      l     i      b    a     i    r    a     V    n    g     i    s    e     D

   s     t    r    a     P      l      l    a    m      S

   s     t    r    s    a    e    c     P    n    a    e    r    g      l    e    r    a    o     L     T

Method Arc welding 1 2 3 1 Resistance welding 1 2 1 1 Brazing 1 1 1 1 Bolts and nuts 1 2 3 1 Riveting 1 2 3 1 Fasteners 2 3 3 1 Seaming, crimping 2 2 1 3 Adhesive bonding 3 1 1 2 Note: 1, very good; 2, good; 3, poor.

3 3 3 2 1 2 3 3

   y     t     i      l     i      b     i      l    e     R

1 3 1 1 1 2 1 2

   e    c    n    a    n    n     i    o    e     t     t    c    n     i    e    a    p    s     M     I    n      f      l    o    a    e    u     t    s    s    s    o    a     i     E     V      C

2 3 3 1 3 2 3 3

2 3 2 1 1 1 1 3

2 1 3 3 2 3 1 2

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

TABLE 12.1 Comparison of various joining methods.

General Summary Joining Process Shielded metal arc Submerged arc Gas metal arc Gas tungsten arc Flux-cored arc Oxyfuel

Operation Manual Auto Au tom mat atic ic Semiautomatic or automatic Manual or automatic Semiautomatic or automatic Manual

Electron Semiautomatic beam,, las beam laser er or automatic beam 1, highest; 5, lowest

Advantage Portable and flexible Hig igh h de depo possition Works with most metals Works with most metals High deposition Portable and flexible Works with most metals

Skill Level Required High

Welding Position All

Low to medium Low to high Low to high Low to high High Medium to high

∗

TABLE 12.2 General characteristics of joining processes. processes.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Current Type ac, dc

Distortion 1 to 2

Cost of   Equipment Low Lo

Flat and horizontal All

ac, dc

1 to 2

Medium

dc

2 to 3

All

ac, dc

2 to 3

Meedium to M high Medium

All

dc

1 to 3

Medium

All

–

2 to 4

Low

All

–

3 to 5

High

∗

Oxyfuel Gas Welding 2100 C (3800 F) °

°

1260 C (2300 F)

Inner cone 3040 to 3300 C (5500 to 6000 F) °

°

Outer envelope (small and narrow)

°

Outer envelope

Acetylene feather

Bright luminous inner cone

Inner cone (pointed)

Blue envelope

°

(a) Neutral flame

(b) Oxidizing flame

(c) Carburizing (reducing) flame

Gas mixture

Filler rod

Welding torch

Molten weld metal

Flame

Base metal

Solidified weld metal (d)

FIGURE 12.2 Three basic types of oxyacetylene flames used in oxyfuel gas welding and cutting operations: (a) neutral flame; (b) oxidizing flame; (c) carburizing, or reducing, flame. (d) The principle of  the oxyfuel gas welding operation. Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Pressure Pressu re Gas Weldi elding ng C2H2 + O2 mixture

Torch withdrawn Torch Flame heating of surfaces Upsetting force Clamp

(a)

(b)

FIGURE 12.3 Schematic illustration of the pressure gas welding welding process; (a) before, and (b) after. after. Note Note the formation of a flash at the joint, which can later be trimmed off.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Heatt Tran Hea Transfer sfer in Weld Welding ing Material Aluminum and its alloys Cast irons Copper Bronze (90Cu-10Sn) Magnesium Nickel Steels Stainless steels Titanium

Specific Energy, u J/mm3 BTU/in3 2.9 41 7.8 112 6.1 87 4.2 59 2.9 42 9.8 142 9.1-10.3 128-146 9.3-9.6 133-137 14.3 204

TABLE 12.3 Approximate specific energy required to melt a unit volume of commonly welded materials.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Heat input  H  l

=

e

V I  v

Welding speed v

=

e

V I  uA

Shielded Shield ed Metal Arc Welding Welding machine AC or DC power source and controls Work cable

Arc

Solidified slag Electrode holder

Coating

Electrode

Electrode

Work

Shielding gas Base metal

Electrode cable

Weld metal

Arc

FIGURE 12.4 (a) Schematic illustration of the shielded metal arc welding process. About one-half of all large-scale industrial welding operations use this process. (b) Schematic illustration of the shielded metal arc welding operation.

7 5

4 1

FIGURE 12.5 A weld zone showing showing the build-up sequence of individual weld beads in deep welds. Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

2 3

6 8

Submerg Sub merged ed Arc Weldi Welding ng Electrode-wire reel Flux hopper Voltage and current control Unfused-flux recovery tube Wire-feed motor Electrode cable Contact tube Workpiece

Voltage-pickup leads (optional)

Weld backing Ground

FIGURE 12.6 Schematic illustration of the submerged arc welding process process and equipment. Unfused flux is recovered and reused.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Gas Met Metal al Arc Weld elding ing Solid wire electrode

Shielding gas

Current conductor Travel

Nozzle

Wire guide and contact tube

Shielding gas Arc

Solidified weld metal Base metal

Molten weld metal (a)

Feed control Control system Gas out Gun control Workpiece

Wire

Gas in Gun

Shielding-gas source

Voltage control Wire-feed drive motor

Welding machine Contactor control

110 V supply

(b)

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

FIGURE 12.7 (a) Gas metal arc welding process, formerly known as MIG welding (for metal inert gas). (b) Basic equipment used in gas metal arc welding operations.

Flux-C Flu x-Cored ored Arc Weld Welding ing Current-carrying guide tube Insulated extension tip

Arc shield composed of vaporized and slag-forming compounds protects metal transfer through arc

Powdered metal, vapor-or gas-forming materials, deoxidizers and scavengers

Solidified slag Molten slag

Arc Base metal

Solidified weld metal

Molten weld metal

Metal droplets covered with thin slag coating forming molten puddle

FIGURE 12.8 Schematic illustration of the flux-cored arc welding process. This operation is similar to gas metal arc welding.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Electrogas & Electroslag Welding Power source

Control panel

Drive rolls Electrode conduit

Wire reel

Welding wire Gas

Wire-feed drive

Oscillator Welding gun

Electrode lead Oscillation (optional)

Water Gas Water out

Welding wire Water in Fixed shoe

Gas Water out Water in

Gas box

Consumable guide tube

Molten slag

Supplementary shielding gas

Work

Molten weld pool

Moveable shoe

Workpiece (ground) lead

Primary shielding gas

Retaining shoe Water in

Water out

FIGURE 12.9 Schematic illustration of the electrogas welding process.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

FIGURE 12.10 Equipment used for electroslag welding operations.

Gas Tun ungs gste ten n Arc Arc Weld Weldin ingg Travel Electrical conductor Tungsten electrode Gas passage Shielding gas Arc

Filler wire

Solidified weld metal Molten weld metal (a)

Inert-gas supply

Cooling-water supply

or DC welder AC

Torch Filler rod Drain Workpiece Foot pedal (optional) (b)

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

FIGURE 12.11 (a) Gas tungsten arc welding process, formerly known as TIG welding (for tungsten inert gas). (b) Equipment for gas tungsten arc welding operations.

Plasma Pla sma Arc Weldi Welding ng Tungsten electrode Plasma gas

 –

 –

Shielding gas Power supply

Power supply +

+ (a)

(b)

FIGURE 12.12 Two types of plasma arc welding processes: (a) transferred and (b) nontransferred. Deep and narrow welds are made by this process at high welding speeds.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Weld Bead Comparisons

Laser welds

(a)

(b)

FIGURE 12.13 Comparison of the size of weld weld beads in (a) electron-beam or laser-beam welding with that in (b) conventional (tungsten arc) welding. Source: American Welding Society, Welding Handbook, 8th ed., 1991.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

FIGURE 12.14 Gillette Sensor razor cartridge, with laser-beam welds.

Original structure

Fusion zone (weld metal)

Heat-affected zone

Fusion Fusio n Weld Charact Characteristi eristics cs

Base metal

Molten weld metal     e     r     u      t     a     r     e     p     m     e      T

Melting point of base metal Temperature at which the base-metal microstructure is affected

(a)

(b)

FIGURE 12.16 12.16 Grain structure structure in (a) a deep weld and (b) a shallow weld. Note that the grains in the solidified weld metal are perpendicular to their interface with the base metal.

Original temperature of base metal

FIGURE 12.15 Characteristics of a typical fusion weld zone in oxyfuel gas welding and arc welding processes.

1 mm 0.1 mm 0.43 mm

145 155

Melt zone

260 330 355

Heat-affected zone

Hardness (HV)

(a)

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

(b)

FIGURE 12.17 (a) Weld bead on a cold-rolled nickel strip strip produced by a laser beam. (b) Microhardness profile across the weld bead. Note the lower hardness of the weld bead as compared with the base metal. Source: IIT Research Institute.

Fusion Defects FIGURE 12.18 Intergranular corrosion corrosion of a weld  joint in ferritic stainless-steel welded tube, after exposure to a caustic solution. The weld line li ne is at the center of the photograph. Source: Courtesy of Allegheny Allegheny Ludlum Corp.

FIGURE 12.19 Examples of various incomplete fusion in welds.

Weld

Weld

Incomplete fusion from oxide or dross at the center of a joint, especially in aluminum

Incomplete fusion in a groove weld

(b)

(c)

Weld Base metal

B

Incomplete fusion in fillet welds. B is often termed bridging !

(a)

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

"

Defects in Welded Joints Underfill

Crack Base metal

Inclusions

Incomplete penetration (a)

FIGURE 12.19 12.19 Examples of various incomplete fusion in welds.

Good weld Overlap

Undercut

Porosity Lack of penetration (b)

(c)

Weld

Toe crack

Transverse crack

Longitudinal crack

Crater cracks

Base metal

Underbead crack

FIGURE 12.20 Examples of various defects in fusion welds.

Weld Weld

Transverse crack Longitudinal crack

Base metal

Base metal (a)

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Toe crack (b)

Weld Cra Crack  ck 

FIGURE 12.22 Crack in a weld bead, due to the fact that the two components components were not allowed to contract after the weld was completed. Source: Courtesy of  Packer Engineering.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Distortion Distor tion in Welds Weld

Weld

Transverse shrinkage

Weld

Longitudinal shrinkage (b)

Angular distortion (a)

Weld

Neutral axis

(c)

(d)

FIGURE 12.23 Distortion and warping of parts after welding, caused by differential thermal expansion and contraction of  different regions of the welded assembly. Warping can be reduced or eliminated by proper weld design and fixturing prior to welding.

Residual stress Comp Co mpre ress ssiv ive e

Base metal

Ten ensi sile le

FIGURE 12.24 Residual stresses developed in a straight butt joint. Source: Courtesy of the American Welding Society. Weld

(a)

(b)

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Distortion Distor tion of Welded Struct Structures ures Rigid frame

Hot zone (expanded)

Contraction

Melt (pushed out)

Internal (residual) tensile stress

No shape change

Distortion

( a)

(b)

(c)

FIGURE 12.25 Distortion of a welded structure. (a) Before welding; welding; (b) during welding, with weld bead placed in joint; (c) after welding, showing distortion in the structure. Source: After  J.A. Schey. Schey.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Tens ensio ion-S n-Shea hearr Test estin ingg Root bend

Longitudinal tension-shear Clamp Roller

Face bend

Weld

Side bend

Transverse tension-shear (a)

(b)

(c)

FIGURE 12.26 (a) Types of specimens for tension-shear testing of welds. (b) Wraparound bend test method. (c) Three-point bending of welded specimens. (See also Fig. 2.21.)

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Tens ensio ionn-Sh Shear ear Tes Testt of Sp Spot ot Wel elds ds

(a)

1. Raised nugget

2.

(b)

Hole left in part Button diameter indicates quality 3. (c)

(d)

FIGURE 12.27 (a) Tension-shear test for spot welds; (b) cross-tension cross-tension test; (c) twist test; (d) peel test.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Roll Bonding & Ultras Ultrasonic onic Welding Force

Mass

Cladding metal

Transducer Transducer

Base metal

Toolholder

DC

polarization supply

Coupling system

Roller

Rolls

Workpiece

Tip

Direction of vibration

Workpiece

AC

power supply

Anvil

FIGURE 12.28 Schematic illustration of the roll-bonding, or cladding, process.

(a)

(b)

FIGURE 12.29 (a) Components of an ultrasonic welding machine for lap welds. (b) Ultrasonic seam welding using a roller.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Friction Frict ion Welding Force

1.

Beginning of flash

2.    h    t   g   n   e    l    t   e   s   p    U  ,   e   c   r   o    F  ,    d   e   e   p    S

Force increased

Speed 3.

Flash

Force

4.

 h e n g t h  U p se t l le

Total upset length

Time

FIGURE 12.31 12.31 Shapes of the fusion zone in friction welding as a function of the force applied and the rotational speed.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

FIGURE 12.30 Sequence of operations in the friction welding process. (1) The part on the left is rotated at high speed. (2) The part on the right r ight is brought into contact under an axial force. (3) The axial force is increased, and the part on the left stops rotating; flash begins to form. (4) After a specified upset length or distance is achieved, the weld is completed. The upset length is the distance the two pieces move inward during welding after their initial contact; thus, the total length after welding is less than the sum of the lengths of the two pieces. If necessary, necessary, the flash can be removed by secondary operations, such as machining or grinding.

(a) High pressure or low speed

(b) Low pressure or high speed

(c) Optimum

Friction Frict ion Stir Welding

Shouldered non-consumable tool Probe

Weld

FIGURE 12.32 The principle of the friction stir welding process. Aluminum-alloy plates up to 75 mm (3 in.) thick have been welded by this process. Source: TWI, Cambridge, United Kingdom.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Resistance Resist ance Spot Welding Electrodes Weld nugget Lap joint

1. Pressure applied

2. Current on

3. Current off, pressure on

4. Pressure released

(a)

Electrodes Electrode Electrode tip

Indentation Sheet separation

Weld nugget

Workpiece

Workpiece (a)

(b)

Heat-affected zone Electrode (b)

FIGURE 12.33 12.33 (a) Sequence in the resistance spot welding operation. (b) Cross-section of a spot weld, showing weld nugget and light indentation by the electrode on sheet surfaces.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

FIGURE 12.34 Two types of electrode electrode designs for easy access in spot welding operations for complex shapes.

Seam & Resist Resistance ance Projection Welding Electrode wheels Electrode wheels Weld nuggets Weld

(a)

Weld

Sheet

(b)

(c)

(d)

FIGURE 12.35 (a) Illustration of the seam welding process, with rolls acting as electrodes. (b) Overlapping spots in a seam weld. (c) Crosssection of a roll spot weld. (d) Mash seam welding.

Force Weld nuggets

Flat electrodes Sheet

FIGURE 12.36 Schematic illustration of  resistance projection welding: (a) before and (b) after. The projections on sheet metal are produced by embossing operations, as described in Section 7.5.2. Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Product Workpiece Projections Force (a)

(b)

Flash & Stud Welding Arc

FIGURE 12.37 Flash welding process for for end-toend welding of solid rods or tubular parts. (a) Before and (b) after.

(a)

(b)

Push

FIGURE 12.38 Sequence of operations in stud arc welding, used for welding bars, threaded rods, and various fasteners on metal plates.

Pull

Push

Stud Ceramic ferrule

Molten weld metal

Arc Workpiece (base metal) 1.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

2.

Weld

3.

4.

Explosion Explosi on Welding Deto De tona nato torr

Expl Ex plos osiv ive e

Deto De tona nato torr

Clad me Clad meta tall (flyer)

Expl Ex plos osiv ive e

Buffer Clad metal

Constantinterface clearance gap

Angular-interface clearance gap

A

Base plate (a)

FIGURE 12.40 Cross-sections of explosion welded joints: (a) titanium (top) on low-carbon steel (bottom) and (b) Incoloy 800 (iron-nickelbase alloy) on low-carbon steel. The wavy interfaces shown improve the shear strength of  the joint. Some combinations of metals, such as tantalum and vanadium, produce a much less wavy interface. If the two metals have little metallurgical compatibility, an interlayer may be added that has compatibility with both metals. {\it Source:} Courtesy Cour tesy of DuPont Company. Company.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Base plate

FIGURE 12.39 Schematic illustration of the explosion welding process: (a) constant interface clearance gap and (b) angular interface clearance gap.

(b)

(a)

(b)

Diffusion Bonding Stop off

1. Core sheet

Bonding pressure

2. Diffusion bonding Gas pressure for forming

Die

Die 3. Superplastic forming

4. Final structure

FIGURE 12.41 Sequence of operations in diffusion bonding and superplastic forming of a structure with three flat sheets. See also Fig. 7.46. Source: After D. Stephen and S.J. Swadling.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7

Brazing Brazi ng & Braze Welding

Base metal

Torch

Brass filler metal Base metal

   h    t   g   n   e   r    t   s    t   n    i   o    J

Flux Filler metal (a)

TABLE 12.4 Typical filler metals for for brazing various metals and alloys.

e  a 

r   s 

t  r  e n 

n     g  t    h 

gt  g  t  h  

FIGURE 12.43 The effect of joint clearance on tensile and shear strength of brazed joints. Note that unlike tensile strength, shear strength continually decreases as clearance increases.

Base Metal Aluminum and its alloys Magnesium alloys Copper and its alloys Ferro errous us and and nonf nonfer erro rous us allo alloys ys (exc (excep eptt alum alumin inum um and and magn magnes esiu ium) m) Iron-, nickel-, and cobalt-base alloys Stainless steels, nickel- and cobaltbase alloys

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

t      r     e   

S    h 

Joint clearance

(b)

FIGURE 12.42 (a) Brazing and (b) braze welding welding operations.

T     e    n    s     i     l     e    s   

Filler Metal Aluminum-silicon Magnesium-aluminum Copper-phosphorus Silv Silver er and and coppe copperr allo alloys ys,, copp copper er-p -pho hosp spho horu russ Gold Nickel-silver

Brazing Temperature ( C) 570-620 580-625 700-925 62 6200-11 1150 50 ◦

900-1100 925-1200

Furnace Brazing & Brazed Joints Filler metal

Filler-metal wire

(a)

FIGURE 12.45 12.45 Joint designs designs commonly used in brazing operations.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

(b)

FIGURE 12.44 An application application of  furnace brazing: (a) before and (b) after. Note that the filler metal is a shaped wire.

Solder Joints (a) Flanged T

(b) Fl Flush la lap

(c) Fl Flanged co corner

(d) Line contact

Bolt or rivet

(e) Flat lock seam

(f) Flanged bottom

FIGURE 12.46 Joint designs commonly used used for soldering.

(g) Gull wing

Crimp

PC board

Wire

(h) Through hole

TABLE 12.5 applications.

(i) Crimped

Types of solders solder s and their

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

(j) Twisted

Solder Tin-lead Tin-zinc Lead Lead-s -sil ilve verr Cadmium-sil Cadmium-silver ver Zinc-alumin Zinc-aluminum um Tinin-silve lver TinTin-bi bism smut uth h

Typical Application General purp os ose Aluminum Stre Streng ngth th at high higher er than than room room tempe tempera ratu ture re Strength Strength at high high temperatures temperatures Aluminum Aluminum;; corrosion corrosion resistance resistance Electronics Elec Electr tron onic icss

Soldering for Circuit Boards Squeegee Tensioned screen

Screen material Paste

FIGURE 12.47 Screening solder paste paste onto onto a printed circuit board in reflow soldering. Source: After V. V. Solberg. Solb erg. Paste deposited on contact area

Emulsion

Contact ar area

Copper land Copper land Plating or coating

FIGURE 12.48 (a) Schematic illustration of the wave soldering process. (b) SEM image of a wave soldered joint on a surface-mount device. See also Section 13.13.

Wetted solder coat Oil or air

Flux Residues Turbulent zone (oil prevents dross) Oil mixed in Turbulent zone (dross formed in air) (a)

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

(b)

Adhesive Bonding

Single taper

Single

Beveled

Double taper

Double

Radiused

Radiused

Increased thickness

Beveled

(a)

(b)

(c)

(d)

Simple

Simple

Beveled

FIGURE 12.49 Various configurations configurations for adhesively bonded joints: (a) single lap, (b) double lap, (c) scarf, and (d) strap.

Peeling force

FIGURE 12.50 Characteristic behavior of (a) brittle and (b) tough and ductile adhesives in a peeling test. This test is similar to peeling adhesive tape from a solid surface. Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

(a)

(b)

Properties Pr operties of Adhesive Adhesivess Impact resistance Tension-shear strength, MPa (103 psi) Peel strength , N/m (lb/in.) Substrates b on onded ∗

Epoxy Epox y Po or 15-22 (2.2-3.2) <

523 (3) Most

Pol olyu yure reth than anee Excellent 12-20 (1.7-2.9)

Modi Mo difie fied d Ac Acry ryli licc Go o d 20-30 (2.9-4.3)

14,000 (80)

5250 (30)

Most smooth, nonpo porrous

Most smo ot oth, nonpo porrous

Cyan Cy anoc ocry ryla late te Po or 18.9 (2.7) <

525 (3)

Most nonporous metals por or plastics -55 to 80 (-70 to 175) No

Service temperature -55 to 120 -40 to 90 -70 to 120 range, C ( F) (-70 to 250) (-250 to 175) (-100 to 250) Heat cure or mixing Yes Yes No required Solvent resistance Excellent Go o d Go o d Go o d Moisture resistance Go od-Excellent Fair Go o d Po or Gap limitation, mm None None 0.5 (0.02) 0.25 (0.01) (in.) Odor Mild Mild Strong Mo derate Toxicity Mo derate Mo derate Moderate Low Flammability Low Low High Low Note: Peel strength varies widely depending on surface preparation and quality. ◦

◦

TABLE 12.6 adhesives.

Anae An aero robi bicc Fair 17.5 (2.5) 1750 (10) Metals, glass, thermosets -55 to 150 (-70 to 300) No Excellent Go o d 0.60 (0.025) Mild Low Low

Typical properties and characteristics characteristics of chemically reactive reactive structural

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Rivets and Stapling

Standard loop

Flat clinch

(a)

(b)

(c)

(d)

Nonmetal Metal channel

(a)

(b)

(c)

(d)

FIGURE 12.51 Examples of rivets: (a) (a) solid, (b) tubular, tubular, (c) split, or bifurcated, and (d) compression.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

FIGURE 12.52 Examples of various fastening methods. (a) Standard loop staple; (b) flat clinch staple; (c) channel strap; (d) pin strap.

Seams & Crimping

FIGURE 12.53 Stages in forming a doublelock seam. See also Fig. 7.23. 1.

2.

3.

4.

FIGURE 12.54 Two examples exampl es of mechanical mechani cal  joining by crimping.

(a)

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

(b)

Snap Fasteners Spring clip Nut

Push-on fastener

Rod-end attachment to sheet-metal part (a)

(b)

(c)

Deflected Sheet-metal cover

Sheet-metal cover

(d)

(e)

Integrated snap fasteners (f)

FIGURE 12.55 Examples of spring and snap-in fasteners fasteners to facilitate assembly. assembly.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Rigid (g)

Design Guideli Guidelines nes for Welding Poor

Good

Poor

Good

Load Load (a)

(b)

Cut not square

Deburred edge

Burr 90°

(c)

(d)

Surface to be machined

(e)

(f)

FIGURE 12.56 Design guidelines for welding. Source: Bralla, J.G. (ed.) Handbook of Product Design for Manufacturing , 2d ed. McGraw-Hill, 1999.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Weld Designs Poor

Go o d

FIGURE 12.57 welding.

Design guidelines for flash

Moment, M

3M

Intermittent welds

Continuous weld

Welds

(a)

(b)

Wel eld d Ba Base se me meta tall

FIGURE 12.58 Weld designs for Example 12.7. Single V groove

Double V groove (c)

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Brazing Designs Good

Poor

Comments Too little joint area in shear

Improved design when fatigue loading is a factor to be considered

Insufficient bonding

FIGURE 12.59 Examples of good and and poor designs for brazing.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Design for Adhesive Bonding Poor

Good

Very good

(b)

(c)

Adhesive

(a)

Adhesive

Rivet

A dhes i v e

S po t wel d (d) Combination joints

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

FIGURE 12.60 Various joint designs in adhesive bonding. Note that good designs require large contact areas for better joint strength.

Design for Riveting

Poor

Good (a)

(b)

(c)

(d)

FIGURE 12.61 Design guidelines for riveting. Source: Bralla, J.G. (ed.) Handbook of Product Design for Manufacturing , 2nd ed. McGraw-Hill, 1999.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education

Case Study: Monost Monosteel eel® Pistons

Oil gallery

Friction welds

(a)

(b)

FIGURE 12.62 The Monosteel Monosteel ® piston. (a) Cutaway view of the piston, showing the oil gallery and friction welded sections; (b) detail of the friction welds before the external flash is removed by machining; note that this photo is a reverse of the one on the left.

Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education