Dissimilar joining of WC-Co to steel by low-temperature brazing

Abstract

In the present study, an Ag-Cu-Zn-Cd alloy was utilized as filler metal in order to braze the cemented carbide/Cr-Mn steel joints, and the effects of brazing time and filler metal thickness on the resultant joints were investigated. The observations showed that by the increment of the holding time, the Cu-Zn (s.s) phase grows and causes the shear strength to increase. With increasing the brazing time from 5 min to 15 min (at 780 °C), the contact angle of wetting reduced from ~40° to ~ 35.5°, and the shear strength increased from ~72.5 MPa to ~93.5 MPa. The evaluation of the fracture surfaces demonstrated the presence of dimple-like morphologies for the bond made at 15 min. The results also indicated that an increase in the interlayer thickness from 60 µm to 160 µm leads to a reduction in the strength.