Stabilization of the interface temperature in laser beam brazing of aluminum alloys with aluminum-based brazing alloys

目前，激光钎焊是汽车工业中镀锌钢的一种成熟的工艺。该技术可以为客户提供高质量的接缝。与钢相比，铝基填充材料的激光钎焊尚未建立。在这种情况下，主要的挑战之一是由于基材的固相温度和填充材料的液相温度之间的差异很小而导致的工艺窗口。铝合金激光钎焊的润湿过程和时间-温度循环具有周期性，这对基材的部分熔化和润湿缺陷是不利的。为了实现铝基钎料对铝合金激光钎焊的可靠钎焊，必须精确调节钎焊与基材界面的温度。该项目是基于湿润过程的周期性行为的假设，因此，界面温度可以通过过程参数的周期性调制来稳定。

Nowadays, laser brazing is a well-established process in the automotive industry for zinc coated steel. The technology enables high seam qualities for joints being visible for the customer. In contrast to steel, laser brazing of aluminum with aluminum based filler material is not established yet. One of the main challenges in this case is the process window due to the small difference between the solidus temperature of the base material and the liquidus temperature of the filler material.The wetting process and the time-temperature cycle show periodic behaviors in laser brazing of aluminum alloys, which are disadvantageous with respect to partial melting of the base material or wetting defects. In order to achieve reliable laser brazing of aluminum alloys with aluminum based filler material the temperature at the interface between braze and base material has to be precisely adjusted. The project is based on the hypothesis that the periodic behavior of the wetting process and, as result, the interface temperature can be stabilized by the periodic modulation of process parameters.