7/31/2019 Lec 9_2 Welding

1/18

Page 28-1

Solid-State Welding Processes

CHAPTER 7-2

7/31/2019 Lec 9_2 Welding

2/18

Page 28-2

Roll Bonding

Figure 28.1 Schematic illustration ofthe roll bonding, or cladding, process

7/31/2019 Lec 9_2 Welding

3/18

Page 28-3

Ultrasonic Welding

(a) (b)

Figure 28.2 (a) Components of an ultrasonic welding machine for lap welds. The lateralvibrations of the tool tip cause plastic deformation and bonding at the interface of theworkpieces. (b) Ultrasonic seam welding using a roller. (c) An ultrasonically welded part.

7/31/2019 Lec 9_2 Welding

4/18

Page 28-4

Friction Welding

Figure 28.3 (a) Sequence of operations in the friction welding process: (1) Left-handcomponent is rotated at high speed. (2) Right-hand component is brought into contact under anaxial force. (3) Axial force is increased; flash begins to form. (4) Left-hand component stopsrotating; weld is completed. The flash can subsequently be removed by machining or grinding.(b) Shape of fusion zone in friction welding, as a function of the force applied and the rotationalspeed.

(a)

(b)

7/31/2019 Lec 9_2 Welding

5/18

Page 28-5

Friction Stir Welding

Figure 28.4 The principleof the friction stir weldingprocess. Aluminum-alloyplates up to 75 mm (3 in.)

thick have been welded bythis process. Source: TWI,Cambridge, U.K.

7/31/2019 Lec 9_2 Welding

6/18

Page 28-6

Resistance Spot Welding

Figure 28.5 (a) Sequence

in resistance spot welding.(b) Cross-section of a spotweld, showing the weldnugget and the indentationof the electrode on thesheet surfaces. This is oneof the most commonlyused process in sheet-metal fabrication and in

automotive-bodyassembly.

7/31/2019 Lec 9_2 Welding

7/18

Page 28-7

WeldingMachine

Design

Figure 28.6 (a)Schematic illustrationof an air-operatedrocker-arm spot-welding machine.Source: AmericanWelding Society. (b)

and (c) Electrodedesigns for easy accessinto components to bewelded.

7/31/2019 Lec 9_2 Welding

8/18

Page 28-8

Examples of Spot Welding

(c)

(a) (b)

Figure 28.7 (a) and (b) Spot-welded cookware and muffler.(c) An automated spot-welding machine with aprogrammable robot; thewelding tip can move in threeprincipal directions. Sheets aslarge as 2.2 m X 0.55 m (88in. X 22 in.) can be

accommodated in thismachine. Source: Courtesy ofTaylor-Winfield Corporation.

7/31/2019 Lec 9_2 Welding

9/18

Page 28-9

Spot Welding Example

Figure 28.8 Robots equipped with spot-welding guns and operated by computer controls, in amass-production line for automotive bodies. Source: Courtesy of Cincinnati Milacron, Inc.

7/31/2019 Lec 9_2 Welding

10/18

7/31/2019 Lec 9_2 Welding

11/18

Page 28-11

High-Frequency Butt Welding

Figure 28.10 Two methods of high-frequency butt welding of tubes.

7/31/2019 Lec 9_2 Welding

12/18

Page 28-12

Resistance Projection Welding

Figure 28.11 (a) Schematic illustrationof resistance projection welding. (b) A

welded bracket. (c) and (d) Projectionwelding of nuts or threaded bosses andstuds. Source: American WeldingSociety. (e) Resistance-projection-welded grills.

7/31/2019 Lec 9_2 Welding

13/18

Page 28-13

Flash Welding

Figure 28.12 (a) Flash-welding process for end-to-end welding of solid rods or tubular parts. (b)

and (c) Typical parts made by flash welding. (d) Design Guidelines for flash welding.

7/31/2019 Lec 9_2 Welding

14/18

Page 28-14

Stud Welding

Figure 28.13 The sequence of operations in stud welding, which is used for welding bars, threaded rods,and various fasteners onto metal plates.

7/31/2019 Lec 9_2 Welding

15/18

Page 28-15

Comparison of Conventional and Laser-BeamWelding

Figure 28.14 The relative sizes of theweld beads obtained by conventional(tungsten arc) and by electron-beam orlaser-beam welding.

7/31/2019 Lec 9_2 Welding

16/18

Page 28-16

Explosion Welding

Figure 28.15 Schematicillustration of the explosionwelding process: (a) constantinterface clearance gap and(b) angular interface clearancegap. (c) and (d) Cross-

sections of explosion-weldedjoints. (c) titanium (top piece)on low-carbon steel (bottom).(d) Incoloy 800 (an iron-nickel-based alloy) on low-carbon steel. Source:Courtesy of E. I. Du Pont deNemours & Co.

(a) (b)

(c) (d)

7/31/2019 Lec 9_2 Welding

17/18

Page 28-17

Diffusion Bonding Applications

Figure 28.16

7/31/2019 Lec 9_2 Welding

18/18

Page 28-18

Diffusion Bonding/Superplastic Forming

Figure 28.17 The sequence of operations in thefabrication of various structures by diffusion bondingand then superplastic forming of (originally) flatsheets. Sources: (a) After D. Stephen and S.J.Swadling. (b) and (c) Rockwell International Corp.