An analysis presents a weld leakage problems of automotive pressure sensor, caused by weld crater cracking. A two-beam laser welding (TBLW) was used to weld a circumferential weld, which undesirably increases the probability of weld leakage by creating two weld end craters on a single weld. Microstructural analysis showed that microsegregation of alloying elements combined with imposed strains causes solidification cracking at the weld end crater. A novel “zigzag” laser power ramp-down was used and the results showed a limited crack propagation by producing significantly shorter discontinuous cracks. In such weld crater endings the leakage is no longer an issue.

分析了汽车压力传感器的焊缝泄漏问题，由焊缝开裂引起。使用双光束激光焊接 (TBLW) 来焊接圆周焊缝，这会在单个焊缝上产生两个焊缝端坑，从而不希望地增加了焊缝泄漏的可能性。显微组织分析表明，合金元素的微观偏析与外加应变相结合，导致焊缝端部弧坑处出现凝固裂纹。使用了一种新颖的“锯齿形”激光功率斜降，结果表明，通过产生明显更短的不连续裂纹，裂纹扩展受到限制。在这种焊缝末端，泄漏不再是问题。