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Veljko Samardzic -215 Engineering Materials and Processes Resistance and Solid- State Welding Processes Chapter 32

Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

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Page 1: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Resistance and Solid-State Welding Processes

Chapter 32

Page 2: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

32.1 Introduction

Page 3: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

32.2 Theory of Resistance Welding

Page 4: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Basic Resistive Welding

FIGURE 32-1 The basic resistance welding circuit.

Page 5: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Resistive Welding Temperature Distribution

FIGURE 32-2 The desiredtemperature distribution acrossthe electrodes and workpiecesduring resistance welding.

Page 6: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Current and Pressure for Resistive Welding

FIGURE 32-3 A typical current and pressure cycle for resistance welding. This cycle includes forging and postheating operations.

Page 7: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Schematic of Resistive Welding

FIGURE 32-4 Thearrangement of the electrodesand workpieces in resistancespot welding.

Page 8: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

32.3 Resistance Welding Processes

Page 9: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Microstructure of a Resistance Weld

FIGURE 32-5 A spot-weld nugget between two sheets of 1.3-mm (0.05-in.) aluminum alloy. The nugget is not symmetrical because the radius of the upper electrode is greater than that of the lower electrode. (Courtesy Lockheed Martin Corporation, Bethesda, MD.)

Page 10: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Tear Test

FIGURE 32-6 Tear test of a satisfactory spotweld, showing how failure occurs outside ofthe weld.

Page 11: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Resistive Welder

FIGURE 32-7 Single-phase,air-operated, press-typeresistance welder withmicroprocessor control.(Courtesy Sciaky Inc., Chicago, IL.)

Page 12: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Spot Welding Application

Page 13: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Spot Welding Seams

FIGURE 32-8 Seam weldsmade with overlapping spotsof varied spacing. (CourtesyTaylor-Winfield Corporation,Brookfield, OH.)

Page 14: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Schematic of Seam Welding

FIGURE 32-9 Schematicrepresentation of theseam-welding process.those

Page 15: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Tube WeldingFIGURE 32-10 Using high- Squeeze rollfrequency AC current to producea resistance seam weld in buttweldedtubing. Arrows from thecontacts indicate the path of thehigh-frequency current

Page 16: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Projection Welding

FIGURE 32-11 Principle ofprojection welding (a) prior toapplication of current andpressure and (b) after formationof the welds.

Page 17: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

32.4 Advantages and Limitations of Resistance Welding

Page 18: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

32.5 Solid-State Welding Processes

Page 19: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Process Summary for RW

Page 20: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Cold Welding

FIGURE 32-12 Small parts joined by cold welding. (Courtesy of Koldweld Corporation, Willoughby, OH.)

Page 21: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Roll Welding

FIGURE 32-13 Examples ofroll-bonded refrigerator freezerevaporators. Note the raisedchannels that have beenformed between the roll-bondedsheets. (Courtesy Olin Brass,East Alton, IL.)

Page 22: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Friction Welding

FIGURE 32-14 Sequence for making a friction weld. (a) Components with square surfaces are inserted into a machine where one part is rotated and the other is held stationary. (b) The components are pushed together with a low axial pressure to clean and prepare the surfaces. (c) The pressure is increased, causing an increase in temperature, softening, and possibly some melting. (d) Rotation is stopped and the pressure is increased rapidly, creating a forged joint with external flash.

Page 23: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Schematic for Friction Welding

FIGURE 32-15 Schematic diagram of the equipment used for friction welding. (Courtesy of Materials Engineering.)

Page 24: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Inertia Welding

FIGURE 32-16 Schematicrepresentation of the varioussteps in inertia welding. Therotating part is now attachedto a large flywheel.

Page 25: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Examples of Friction Welding

FIGURE 32-17 Some typicalfriction-welded parts. (Top)Impeller made by joining achrome–moly steel shaft to anickel–steel casting. (Center)Stud plate with two mild steelstuds joined to a square plate.(Bottom) Tube componentwhere a turned segment isjoined to medium-carbon steeltubing. (Courtesy of Newcor BayCity, Division of Newcor, Inc.,Royal Oak, MI.)

Page 26: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Stir Welding

FIGURE 32-18 Schematic of the friction-stir welding process. The rotating probe generates frictional heat,while the shoulder provides additional friction heating and prevents expulsionof the softened material from the joint. (Note: To provide additional forgingaction and confine the softened material, the tool may be tilted so thetrailing edge is lower than the leading segment.)

Page 27: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Example of Stir Welding

FIGURE 32-19 (a) Top surfaceof a friction-stir weld joining 1.5-mm- and 1.65-mm-thickaluminum sheets with 1500-rpmpin rotation. The welding toolhas traversed left-to-right andhas retracted at the right of thephoto. (b) Metallurgical crosssection through an alloy 356aluminum casting that has beenmodified by friction-stirprocessing.

Page 28: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Features of Stir Welding

Page 29: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Schematic of Ultrasonic Welding

FIGURE 32-20 Diagram of theequipment used in ultrasonicwelding

Page 30: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Application of Ultrasonic Welding

Page 31: Veljko Samardzic ME-215 Engineering Materials and Processes Resistance and Solid-State Welding Processes Chapter 32

Veljko SamardzicME-215 Engineering Materials and Processes

Explosive Welding

FIGURE 32-21 (Left) Schematic of the explosive welding process. (Right) Explosive weld between mild steel and stainless steel, showing the characteristic wavy interface.