Pulsed laser welding was used to join ultra thin Inconel 718 alloy foils whose thickness was 0.2 mm. A fixture was designed to obtain the edge joint. The joint geometry and hot cracking were both observed on the cross sections. The relationship between the height, width of the joint and the energy density were fitted as linear functions. The effect of heat input on the hot cracking in the edge joint was obtained. It was shown that a hot cracking occurred during the solidification of the molten metal under laser heating. The crack initiated at the gap between the foil pair and propagated along the Laves phase with low melting point. The crack length could be reduced by applying low heat input. Tearing tests were conducted to evaluate the influence of the cracking on the mechanical performance of edge joints. There existed two failure modes for the edge joint under a tear loading. When the crack length exceeds 106.9 μm the hot crack starts to propagate and the tear loading decreases with crack length increasing. A finite element model was established to simulate the stress evolution during the cooling stage. The main reason of crack initiation and propagation were both presented.

使用脉冲激光焊接来连接厚度为0.2毫米的超薄Inconel 718合金箔。设计了一种夹具来获得边缘连接。在横截面上均观察到接头的几何形状和热裂纹。接头的高度，宽度和能量密度之间的关系被拟合为线性函数。获得了热输入对边缘接缝中热裂纹的影响。结果表明，在激光加热下熔融金属的凝固过程中发生了热裂纹。裂纹在箔对之间的间隙处开始并沿拉夫斯相以低熔点传播。可以通过施加低热量输入来减小裂纹长度。进行了撕裂测试，以评估裂纹对边缘接头机械性能的影响。撕裂载荷作用下的边缝存在两种失效模式。当裂纹长度超过106.9μm时，热裂纹开始传播，并且随着裂纹长度的增加，撕裂载荷降低。建立了有限元模型来模拟冷却阶段的应力演化。提出了裂纹萌生和扩展的主要原因。