Preparation of TiC/Fe composite layer on the surface of GCr15 and its binding performance with matrix

In this study, A TiC/Fe composite layer was prepared on the surface of GCr15 using hot pressure diffusion in situ reaction. X-ray diffractometer (XRD), scanning electron microscopy (SEM), automatic scratching instrument and microhardness apparatus were used to characterize the phase composition, microstructure, interface binding properties of the composite layer and changes in microhardness. The results show that the thickness of the TiC/Fe composite layer after insulation for 2 h, 4 h and 6 h at 1 000 ℃, 40 MPa is 5 μm, 7 μm and 10 μm, respectively, the thickness of the composite layer is uniform, the interface with the matrix is flat. The surface phase composition is only TiC and α-Fe phase, and the microhardness of the composite layer is up to 2 453.7 HV0.05, which is about 5 times that of the bearing steel matrix. Micro scratching and tensile tests show that the critical load of the composite layer bonding to the matrix interface at 1 000 ℃, 40 MPa for 4 h is 58.5 N, and the interfacial bonding strength is greater than 221 MPa. The results show that the TiC/Fe composite layer on the surface of GCr15 prepared by hot compression diffusion in situ has excellent binding properties and good matrix protection effect.