International Journal of Engineering Science and Application, cilt.2, ss.47-53, 2018 (Hakemli Dergi)
In recent years, friction stir spot welding (FSSW) is widely used as a joining method espically in the automotive industry. This method has been found of use in joining of plastics. The welding parameters and the tool material have very significant effects in FSSW joining. Welding tool material is very important in FSSW because the tool generates heat in welding and cooling rate in the solidification period. In this study, the dependence of the lap shear fracture load on the FSSW welding parameters (tool rotational speed, tool plunge depth, tool dwell time) and different heat transfer coefficient of the welding tool have been investigated. “The highest -the better” quality control characteristic using the Analysis of Variance (ANOVA) method was used to find the optimum welding parameters. The experiments were arranged by using Taguchi‟s L16 orthogonal array. The results have been analyzed by the graphical methods and numarical data. The most spectucular result of this study was the effect of tool material on the weld strength. The welding tool heat transfer coefficient and the tool rotation speed were observed very effective and important on FSSW weld strength of high density polyethylene sheets, Finally, the improvement in the weld strength from the initial welding parameters to the optimal welding parameters was found about 22%.