Laser fusion welding of alumina ceramics based on simultaneous preheating

Crack defects in ceramic welding are a significant challenge in electronic packaging that requires urgent resolution. In this study, fiber laser-based welding was employed to join 1 mm thick Al2O3 ceramic plates. The investigation focused on weld surface formation, crack defects, and performance attributes across varying heat input and preheating temperatures. The findings indicate a propensity for crack initiation at the weld center or within the base material during Al2O3 ceramic laser welding. Nonetheless, the susceptibility to cracking in Al2O3 welded joints can be mitigated, and joint flexural strength enhanced by adjusting heat input or by introducing a preheating treatment. The flexural strength peaked at a preheating temperature of 100 degrees C, exhibiting a 112 % increase compared to non-preheated welded joints. In addition, the best matching relationship between heat input and the preheating temperature was obtained through numerical calculations. The relationship between heat input and preheating temperature determines the cracking tendency region, and based on their interrelation, the cracking tendency region is partitioned into three distinctive regions. Subsequently, the three regions were experimentally validated, with results exhibiting a high degree of congruence, thereby offering significant guidance in the selection of laser welding parameters for Al2O3 ceramics.