Development of nitrided selective wave soldering tool with enhanced lifetime for the automotive industry

The aim of our research is to develop an economic material combination exhibiting good wetting with solder alloy melts and enhanced lifetime against erosion in lead-free soldering applications. Iron-nitrides have strong bonds compared to metals, therefore they are expected to have increased resistance against erosion in solder melts compared to iron soldering tools. The first step of our research is to find the proper substrate material for nitride coating to obtain the desired wetting behaviour. The present paper focuses on the substrate material selection through wetting examinations of nitrided W302, 42CrMo4 and C45 steels with SAC 305 solder alloy melt. It was found that the substrate composition strongly affects the wetting contact angle. The best wetting was achieved with the C45 type steel substrate. The correlation between substrate composition, compounds formed during nitriding and wetting behaviour is discussed.