유한요소법에의한 마찰교반용접시 AZ31마그네슘 합금의 유동 및 강도 해석

Abstract

Friction Stir Welding is a solid state joining method patented in 1991 by The Welding Institute(TWI). It is widely used for joining light metals such as Al and Mg alloys. Foreign vehicle manufacturing companies have been applying Friction Stir Welding to car body welding, but domestic companies are in the beginning of feasibility study. Therefor, lots of experimental and analytical study is needed. In This paper, the design of experiment with two-way factorial design is adopted and optimum values of welding variables including the welding speed and rotation speed were found to improve the tensile properties of the Friction Stir Welded joints of AZ31 Mg alloy plates. Also, three-dimensional finite element modeling of the Friction Stir Welding of AZ31 Mg alloy plates were carried out by analysis program named SYSWELD such as experimental conditions. And temperature field and von mises stresses were obtained and valid of numerical analysis was verified by compare experimental results with numerical analysis results. For the Friction Stir Welding process, the rotation speed and welding speed conditions were changed and analyzed the influence of welding variables on the tensile properties. Tool with shoulder diameter of 12mm and pin diameter of 3.5mm was used and the other tool parameters were constant. The welding direction was aligned with the material rolling direction, and dimensions of the AZ31 Mg alloy plates were 100×400×2 mm. As far as this work is concerned, the optimal Friction Stir Welding conditions were determined as the rotation speed, 1200rpm and welding speed 200mm/min. Also, it’s founded the analytic thermal and mechanical field was in a good agreement with the experimental results, but the other welding parameters are needed and examined.