Tungsten-copper / stainless steel Bi-material parts by 2C-MIM

Abstract

The paper reports on investigations for two component injection moulding (2C-MIM) of bi-material parts of W-Cu and the stainless steel 316L. The feasibility of joining these different materials by co-sintering was investigated. A significant mismatch in shrinkage of tungsten and 316L was observed by sinter dilatometry. It could be compensated by adjusting the powder particle size of the stainless steel. MIM parts of both materials were sinter joined followed by infiltration with Cu powder. The tungsten-copper / stainless steel interfaces were characterized by optical microscopy. The results show that it is possible to produce an interface of tungsten-copper and stainless steel by co-sintering and infiltration. The material combination in a functionally graded part would combine the high electrical and thermal conductivity of W-Cu with a ductile and rather cheap stainless steel substrate predestinated for electrical and thermal management applications