A study on the Jointing Condition and the Reliability Analysis of Tensile-Shear Strength for 6063-T5 Aluminum Alloy by Resistance Spot Welding

• Main Author: 郭致誠
• Other Authors: 呂傳盛
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/02759059989030888307

碩士 === 國立臺灣師範大學 === 工業教育研究所 === 90 === Due to the requirement of lightweight, aluminum alloy has been applied extensively in 3C/information and automotive industry. And the resistance spot welding is the key technique at the jointing method of aluminum alloy sheet, the advantages of resistance spot welding are its short process, high speed, adaptability for automation and flat welding piece. Because of its high electrical as well as thermal conductivities and lower melting point, aluminum alloy needs high current, accurate control of welding time, acceptable welding pressure to match up. The material of this research is commercial aluminum alloy 6063-T5 and the alternating-current transformer machines have been used to find the suitable welding parameters by observing the microstructure and tensile-shear strength. The correlation of the parameter and tensile-shear strength by the tensile-shear test has been conferred, too. The Weibull analysis used to discuss the reliability of joining properties for aluminum alloy 6063-T5 sheet that used the single-phase alternating-current transformer machines to weld. According to the observation in this study, the microstructures that aluminum alloy 6063-T5 after welded are fusion zone, partially fusion zone, heart affect zone and base metal. The highest is base metal, the second is heart affect zone and fusion zone and the lowest is partially fusion zone of the micro-hardness distribution. To observe the nugget diameter that only the nugget diameter of the thickness of 1.0mm reach the standard size. According to the result of tensile-shear test, the different welding time and electrode force both affect the tensile-shear strength. Under the different condition of parameters, make the reliability analysis of tensile-shear strength. When the location parameter (t0) is zero, the range of Weibull modulus is 4.38~9.55, indicating wear-out mode. Take the highest correlation coefficient of location parameter to forecast the minimum life and make up nugget diameter and tensile-shear strength. The best parameter of the specimen of 1.0mm is 17.3kA of welding current, 10cycles of welding time and 100kgf electrode force.