Studies on the Friction Stir Welding of Aluminum Alloy Thick Plate using a Novel Welding Tool

• Main Authors: Kuang-ming Cho, 卓光明
• Other Authors: Yuang-Cherng Chiou
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/98983997598024860168

碩士 === 國立中山大學 === 機械與機電工程學系研究所 === 101 === In this study, an equipment suitable for the friction stir welding of the thick plates was constructed, and the effects of the operating parameters on the welded defects were investigated. A new welding tool was used to improve the defects caused by the insufficient heat at the low rotational speeds. By changing the shoulder diameter of the tool (D), the pin diameter (d), the rotational speed, and the tilt angle, experimental results showed that when the D / d ratio was greater than 2.5, the effect of pin diameter on the defect was insignificant. However, at D / d ratio less than 2.5, the smaller pin diameter could improve this defect. When the embedded-type tool with the pin was used to weld the thick plates, the defects can be improved because the sufficient heat was provided by this tool, so that the thickness of stirred zone was increased to 10.5 percent compared to the plain tool. Meanwhile, a method was proposed to estimate the required rotational speeds under different diameters of the shoulder. A diagram, including the excess heat region, the sound joints region, and the insufficient heat region, was established in terms of the rotational speed and the shoulder diameter.