鋁合金6063-T5電阻點銲接合條件及拉剪強度之可靠度分析

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

郭致誠

指導教授 ： 呂傳盛 ； 程金保

國立臺灣師範大學/科技學院/工業教育學系/碩士(2001年)

摘要

隨著輕量化的需求，鋁合金在3C/資訊及汽車產業的應用日益增加，而電阻點銲法是鋁合金薄板接點的關鍵技術，其具有加工時間短、生產速度快、容易自動化及加工表面平整等優點。
鋁合金具有高導電性、高熱傳導性和低熔點等特性，需要高電流、精確的時間控制及適當的銲接壓力等因素相互配合。本研究使用6063 - T5鋁合金商用板材為研究對象，配合目前業界佔有率最廣的單相交流點銲機，經由不同製程參數的控制，觀察金相組織、拉剪強度，以尋找適當的接合條件。透過拉剪試驗，探討不同參數與拉剪強度之關係；並利用韋伯統計分析，討論6063 - T5鋁合金使用單相交流點銲機銲接之可靠度。
本研究經由顯微組織觀察得到結果顯示6063 - T5鋁合金經點銲後，其顯微組織有熔融區、部份熔融區、熱影響區及母材等部份；其微硬度分佈以母材最高、熱影響區次之，再來是熔融區，部份熔融區微硬度最低。觀察其銲核尺寸，僅有厚度1.0㎜點銲後銲核尺寸達到標準範圍。經由拉剪試驗得知不同的通電時間與電極加壓力皆會影響銲接件之拉剪強度。將拉剪試驗所得，在不同條件下之拉剪強度進行可靠度分析，當位置參數t0=0時，m值分佈在4.38~9.55，屬於磨耗故障型；取相關係數最高之位置參數預測最小壽命，再配合銲核尺寸及拉剪強度等，得到厚度1.0㎜試片之點銲最佳製程參數為熔接電流17.3kA、通電時間10cycles、電極加壓力100kgf。

關鍵字

可靠度分析 ； 鋁合金 ； 電阻點銲

並列摘要

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.

並列關鍵字

reliability analysis ； aluminum alloy ； resistance spot welding

參考文獻

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