Dissimilar brazing of cemented carbide to steel using a pure copper as filler metal

Dissimilar brazing of cemented carbide to steel using a pure copper as filler metal

Due to the higher production cost of the monolithic cemented carbide tools as well as their brittle nature, these cemented carbides such as WC-Co are usually joined to a steel. This research investigates the use of pure copper as an interlayer to dissimilar braze the WC-8 Wt.%Co cermet to AISI 4140 steel. The results indicate the formation of a Cu-Fe-Co reaction layer at the joint interface in addition to the formation of precipitates in the joint area. Also the micro hardness measurements indicated considerably higher values near the both interfaces in compared with the copper interlayer zone. The shear strength for the produced joint obtained 138 MPa, which is an appropriate strength for the WC-Co/steel dissimilar brazed joints. However, using other joining strategy or filler materials via prevention the formation of cobalt depletion zone in joint area can enhance the joint strength.