赵平林,王瑞杰,刘国寿,廖祥雲

• 1:昆明理工大学机电工程学院
• 2:昆明理工大学建筑工程学院

摘要(Abstract)：

对3 mm厚的2A12/6061异种铝合金板材进行搭接钨极惰性气体保护焊(TIG),利用光学显微镜、显微硬度仪、扫描电镜和疲劳实验机等对接头的疲劳性能进行分析。在实验结果的基础上，对搭接试样建立有限元模型，采用热点应力法预测接头的疲劳寿命，并与实验结果进行比较。结果表明：焊缝区组织为均匀的等轴晶，2A12侧焊缝与母材熔合较差，且与母材强度差异较大，导致2A12侧焊趾处更容易产生冶金缺陷和较大的应力梯度，进而加速疲劳裂纹的萌生；在不同载荷水平下，试件断裂位置均位于强度差异较大的2A12侧焊趾处，呈脆-塑性复合断裂特征，焊趾处冶金缺陷及焊缝局部强度差异为影响接头疲劳性能的主要因素。寿命预测结果表明：采用考虑板厚效应的热点应力法预测寿命准确，误差在两倍误差带内，采用IIW推荐的FAT40 S-N曲线是安全可靠的。

关键词(KeyWords)： 异种铝合金;TIG焊;疲劳强度;热点应力法;疲劳寿命

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金(51065012)

作者(Author): 赵平林,王瑞杰,刘国寿,廖祥雲

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