Visualization of material flow phenomenon during friction stir welding

A lot of papers have been appeared the clarification of material flow in friction stir welding. When aluminum alloy was used, metal flow during processing is imaged by metallurgical observation after friction stir welding process. It succeeded in taking a material flow phenomenon movie during friction stir with polymer plastics in this paper. This direct observation is revealed that two whirlpools occurred while friction stir resulting influence of pin and shoulder rotation was generated frictional heat. According to the changing of tool type, location of weld imperfection was transferred into behind the tool. In the use of left screw pin, location is move over revolutional movement the end of the pin during preheating time.