Abstract An adaptation of vaporizing foil actuator welding (VFAW), a solid-state impact welding technique for producing similar JSC590R and 6061-T6 spot-welded joints was used in this study and the mechanical and fatigue properties of the joints were characterized using lap-shear testing, microhardness measurements, optical imaging and fatigue testing and the results compared with those of resistance spot welding (RSW) joints. Results indicated that the VFAW joints had improved strength and energy absorption compared to RSW joints for both the material combinations, however the strength of JSC590R-JSC590R VFAW welds were found to be lower than RSW when corrected for nugget size. Microhardness measurements in VFAW joints showed constant hardness values across the weld length signifying the absence of a heat affected zone, whereas softening was observed in RSW joints. Optical imaging revealed the homogeneity in microstructure of VFAW joints and the inhomogeneous distribution of the microstructure in RSW joints. For JSC590R members, fatigue resistance was equivalent for VFAW and RSW, whereas improved fatigue properties were observed for 6061-T6-6061-T6 VFAW welds. Fatigue strength scaled with static strength in a predictable way and was mostly affected by the shape and type of notch formed at the end of the nugget.

中文翻译：

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点冲击焊缝的基准强度和疲劳性能

摘要 本研究采用汽化箔致动器焊接 (VFAW)，一种固态冲击焊接技术，用于生产类似的 JSC590R 和 6061-T6 点焊接头，并使用搭接对接头的机械和疲劳性能进行表征。剪切试验、显微硬度测量、光学成像和疲劳试验，并将结果与​​电阻点焊 (RSW) 接头的结果进行比较。结果表明，与两种材料组合的 RSW 接头相比，VFAW 接头具有更高的强度和能量吸收，但是发现 JSC590R-JSC590R VFAW 焊缝的强度在校正熔核尺寸后低于 RSW。VFAW 接头的显微硬度测量表明，整个焊缝长度的硬度值恒定，表明不存在热影响区，而在 RSW 接头中观察到软化。光学成像揭示了 VFAW 接头微观结构的均匀性和 RSW 接头微观结构的不均匀分布。对于 JSC590R 构件，VFAW 和 RSW 的抗疲劳性相当，而 6061-T6-6061-T6 VFAW 焊缝的疲劳性能得到改善。疲劳强度以可预测的方式与静态强度成比例，并且主要受金块末端形成的凹口形状和类型的影响。