1. Chapter 32: Resistance and Solid-State Welding Processes
DeGarmo’s Materials and Processes in Manufacturing

2. 32.2 Theory of Resistance Welding

3. Basic Resistive Welding
FIGURE 32-1 The basic resistance welding circuit.

4. Resistive Welding Temperature Distribution
FIGURE 32-2 The desired
temperature distribution across
the electrodes and workpieces
during resistance welding.

5. 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.

6. Schematic of Resistive Welding
FIGURE 32-4 The
arrangement of the electrodes
and workpieces in resistance
spot welding.

7. 32.3 Resistance Welding Processes

8. 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.)

9. Tear Test FIGURE 32-6 Tear test of a satisfactory spot
weld, showing how failure occurs outside of
the weld.

10. Resistive Welder
FIGURE Three-phase, air-operated, press-type resistance welder with microprocessor control. (Courtesy Sciaky Inc., Chicago, IL.)

11. Spot Welding Seams FIGURE 32-8 Seam welds made with overlapping spots
of varied spacing. (Courtesy
Taylor-Winfield Corporation,
Brookfield, OH.)

12. Schematic of Seam Welding
FIGURE 32-9 Schematic
representation of the
seam-welding process.
those

13. Tube Welding FIGURE 32-10 Using high- Squeeze roll
frequency AC current to produce
a resistance seam weld in buttwelded
tubing. Arrows from the
contacts indicate the path of the
high-frequency current

14. Projection Welding FIGURE 32-11 Principle of
projection welding (a) prior to
application of current and
pressure and (b) after formation
of the welds.

15. Process Summary for RW