Effect of Brazing Temperature on the Microstructure and Chosen Properties of WC–10Ni/NiCrBSi Composite Coatings Produced by Vacuum Cladding from Flexible Coated Cloths

Abstract

Three kinds of WC–10Ni/NiCrBSi composite coatings were prepared on the surface of Q235 carbon steel at 1015, 1055, and 1095 °C by vacuum brazing. The microstructure and properties of the composite coatings were investigated. The results showed that various reaction layers appeared at the bonding area of the coatings and the substrate. As the brazing temperature increased, the reaction layer between the solder and the hard phase gradually decreased and disappeared at 1095 °C. Simultaneously, the size of gray-white massive phases with a large amount of W in the brazing layer decreased gradually. When the brazing temperature increased, the Fe content markedly increased in the reaction layer of the matrix and the solder, indicating that the increase in brazing temperature was beneficial for metallurgical bonding between the coating and the substrate. Interface bonding strength and wear resistance were enhanced by the increase in brazing temperature; however, the microhardness of the composite coating section decreased. The interface bonding strength reached 362.9 MPa and the wear loss reached a minimum at 1095 °C.