Simplified temperature measurement system at tool tip and shoulder during FSW and Spot FSW

FSW and Spot FSW have been foot lighted into the application of light automobile assembly, which seem to be the most effective for preventing the global warming. Spot FSW has characterized as several merits against conventional resistance spot welding. Joints of Spot FSW are achieved relatively higher shear strength than RSW using less electrical energy input to make joints. The temperature of tool tip is anticipated the critical parameters on to the weld quality and weld joint strength. However, measuring of tip temperature seems to be not so easy due to high rotation of tool. We developed simple procedure to measure the tip of tool by rotating data logger with spindle. After Spot FSW, stored data are transferred to PC for analyzing of process from the logger. Specification of data logger is 4 MB memory with 2 channel thermo-couples and variable sampling intervals depending on the purpose, such as Spot FSW or conventional FSW. Main results are as follows: tip temperature is depending on the rotation speed of tool reaching at 480 – 510 C but temperatures of shoulder do not influenced in case of spot FSW. Measured results show thermal distribution is correlated with probe temperature and material ones. Center of probe temperature is the highest, and sidewall of probe and shoulder in temperatures order.