The Study On Friction Stir Welding Techoloy Of LD10CS Alloy

Friction stir welding (FSW) is a novel solid-state joining technique. As compared to the conventional fusion welding methods, FSW has many advantages, such as low deformation of work piece, absence of cracking and gas cavity. So it is suitable for the very material welding which could not be welded by fusion welding methods. This paper focuses the research on the FSW technology of LD10CS aluminous alloy plate of three kinds thickness. And the formation of the weld, the mechanical properties of the joints, and the microstructures of the weld are studied to fix the feasible FSW technology.The results of the weld formation show that the welding parameters play an important role in the formation of the weld. Only if the welding parameters are feasible, the good-quality joints could be formed. In this article, the welding parameters are fixed which the good-quality joints are formed.The study on the mechanical properties of the joints shows that the welding parameters have great effect on the joints mechanical properties. The best quality joint is respectively achieved in the best welding the best parameters: 5mm joint tensile strength coefficient is 84%; 7mm joint tensile strength coefficient is 80%. To achieve the best-quantity weld, the orthogonal array is used to 10mm-thick plate welding. 10mm joint tensile strength coefficient is 77%.The study on microstructure indicates that the grains of every zone are different. And the grain size in the same zone is different. With the increasing of the welding speed, the grain size in weld nut zone declines, while the TMAZ grain size increases firstly then declines. The precipitates size is decline with the increasing of the welding speed.