Effect of Brazing Temperature on the Microstructure and Property of Vacuum Brazed WC-Co and Carbon Steel Joint

The effect of brazing temperature on the properties of brazed joints between WC-Co hard alloy and SAE1045 carbon steel using Cu and ASTM C52100 bronze metal as insert fillers were investigated. A vacuum brazing furnace was employed to conduct the experiment with different sets of operational parameters (brazing temperature, bonding time and filler) were used. The experimental result shows that Fe-Co-Cu alloy layer was formed at the WC-Co/Cu filler interface. With increased brazing temperature and bonding time, the thickness of the Fe-Co-Cu layer increases. From the shear test, the maximum shear strength is 320±10 MPa for the joint brazed at 1140°C for 15 min using Cu filler. The shear strength of WC-Co/C52100/SAE1045 brazed joints was better than WC-Co/Cu/SAE1045 brazed joints. The increase of bonding time of WC-Co/C52100/SAE1045 joints improved the shear strength slightly.