Developed And The Heat Source Model Of Friction Stir Welding Machine

Friction stir welding (FSW) was invented by TWI (The Welding Institute) in Cambridge UK in 1991, it is well known that this economical joining method has excellent welding property and also has advantage in protecting environment. FSW is finding vast applications in the space flight apparatus, aviation production, shipbuilding, high speed train, natural gas packet, automotive industry instead of GMAW process. It will be an important revolution in joining high strength aluminum and its alloy. Although FSW has short history, welding workers has made great progress in FSW, including its principle, materials welded, welding machine and its application.FSW machine is a critical technology of researching FSW. The rotary speed range of friction tool should vary widely and the tool should work steadily during the welding process; The torque of tool should also be big enough so that much heat is generated in time. The power of the FSW machine should be adjusted easily when the materials welded have different dimension during the different welding process, so adjustable-frequency technology is adopted in this machine. This paper presents the principle, constitution, capability of this machine, lower limit value and upper limit value control method, calculation of the power is also discussed in this paper.The temperature field of FSW also has been studied extraordinarily by many welding workers, there are many solutions to ordinary friction welding temperature field, such as finite element analysis, method of finite difference etc, but the temperature field of FSW has not been researched deeply. The welding field is infuenced by many factors, such as dimesion of the friction tool pin, rotory speed, torque and welding velocity,etc. Emulation is a effective method to meaure and control the FSW temperature field, so heat source model is established and put into computer with ANSYS (A kind of finite element analysis software). Stationary and mobile heat resource formulas are expounded. Then discuss the verification of this model under specific condition in this paper. In the end, some useful advice about temperature field of FSW is given to the coming research.