The effect of Cu interlayer on microstructure and strength in brazed joint of WC-Co with DC53 steel

DC53 cold work-tool steel is recently developed and improved steel with high hardness and good toughness characteristics. In this work, vacuum brazing of WC-Co cemented carbides with DC53 steel was performed to produce dissimilar joint of WC-Co/DC53 using multi filler metals of Cu58Zn, Ag45CuZn, and Cu as an interlayer. The effect of Cu interlayer on the shear strength and microstructure characteristics in WC-Co/DC53 joint was investigated. Results show that the shear strength in WC-Co/DC53 joint using Cu interlayer between Cu58Zn and Ag45CuZn filler metals is 257 MPa, which is much higher than that without Cu interlayer. The fracture morphology shows some ductile feature close to WC-Co side. This is attributed to the formation of more alpha-Cu, Ag solid solution, and Ag-Cu eutectic phase playing the role of stress relief in the WC-Co/DC53 joint. In addition, Cu interlayer also prevents the diffusion of Co element in the WC-Co towards DC53 steel during brazing to ensure the toughness of WC-Co side.

Automated summary

In this study, WC-Co cemented carbides were successfully brazed with DC53 steel using Cu interlayer, which resulted in improved shear strength and toughness characteristics of the WC-Co/DC53 joint.