Analysis of Temperature and Plastic Flow during Friction Stir Spot Welding Using Particle Method

• Published in: Journal of thermal science and technology (Japan Society of Mechanical Engineers) Vol. 4; no. 2; pp. 260 - 271
• Main Authors: Shigeki HIRASAWA, Harsha BADARINARAYAN, Kazutaka OKAMOTO, Toshio TOMIMURA, Tsuyoshi KAWANAMI, Shigeki HIRANO
• Format: Journal Article
• Language: English
• Published: The Japan Society of Mechanical Engineers 01-01-2009
• Subjects: friction stir spot welding; manufacturing process simulation; particle method; plastic deformation; temperature distribution
• ISSN: 1880-5566
• DOI: 10.1299/jtst.4.260

Friction stir spot welding (FSSW) is a new metal-joining process, and a numerical simulation code to calculate optimal welding conditions is desired. In this paper, we analyzed temperature distribution and plastic deformation flow during the FSSW process with the fluid flow model and the elastic-plastic deformation model using the particle method. Spot welds are made with a cylindrical pin tool having flat shoulder with a fixed tool rotational speed. Simulation results predict an axisymmetric temperature distribution with the temperature below the tool in the region of 300 °C. The material flow predicted by the elastic-plastic deformation model is similar to experimental results. The model predicts the material flow at the pin periphery is in the upward direction. Near the shoulder, there are two flow patterns observed - beneath the shoulder, the material is pushed downward due to the force acting from the shoulder face, whereas on the shoulder periphery the material flows upward and outward due to extrusion of the material that is caused by the shoulder plunge. This extruded material shows up on the specimen surface as burr.