2014 年 80 巻 817 号 p. SMM0249
In order to investigate possibility of application of friction stir process to plastics, effects of process parameters such as rotation speed and plunging speed of a tool on temperature distribution during FSSW (Friction stir spot welding) were studied in experimentally as well as analytically in PVC (Polyvinyl chloride). Joining strength of FSSWed PVC joint was evaluated under tensile shear loading. According to the results of temperature measurement, the maximum temperature observed during the process was lower than the melting temperature and thermal decomposition temperature of PVC. Effect of rotation speed of a tool was significant for change in the maximum temperature, but that was not significant for change in size of area friction stirred. Plunging speed significantly affected the maximum temperature and the temperature distribution. It was considered that the size of area friction stirred would be predicted based on the temperature distribution, because size of area with temperature above grass transition temperature of PVC almost coincided with size of area friction stirred. According to result of tensile shear test, it was speculated that the strength of the joint could be controlled by plunging speed, but not rotation speed because of that plunging speed strongly affected the temperature distribution in FSSWed PVC joint during the process. Loading mode changed with change in the stir zone size affected the tensile shear strength of the joint.
