摘要 WC7Co/Ti6Al4V composite coatings are deposited on the pure Ti substrate by pulse laser cladding (LC). During the laser melting process, the decomposition of WC7Co particles will lead to the evolution of microstructure and phases, which is directly related to the wear resistance and mechanism of composite coating. The microstructural evolution, phase composi- tions and interface reaction of WC7Co/Ti6Al4V composite coating were examined by scanning electron microscopy, energy- dispersive spectrum and X-ray diffraction (XRD). The hardness of different structures and abrasive resistance of composite coating were measured. The results show that the typical microstructure of LC WC7Co/Ti6Al4V composite coating can be classified into dissolved WC7Co composite structure and un-dissolved WC7Co structure. According to XRD results, there are Ti solid solution, W, TiC, VC, Co3W3C and secondary W2C in composite coating. The eutectic structure formed by the dissolved WC7Co particles consisted of W, W2C, TiC and β-Ti solid solution. The mean hardness of different structures exhibits a significant gradient distribution in composite coating. A reaction layer composed of TiC, W and W2C is also generated onto the interface between un-dissolved WC7Co particles and Ti6Al4V alloy matrix. The abrasive mechanisms of WC7Co/Ti6Al4V composite coating are mainly adhesive wear and oxidation wear during the dry sliding process.
Abstract：WC7Co/Ti6Al4V composite coatings are deposited on the pure Ti substrate by pulse laser cladding (LC). During the laser melting process, the decomposition of WC7Co particles will lead to the evolution of microstructure and phases, which is directly related to the wear resistance and mechanism of composite coating. The microstructural evolution, phase composi- tions and interface reaction of WC7Co/Ti6Al4V composite coating were examined by scanning electron microscopy, energy- dispersive spectrum and X-ray diffraction (XRD). The hardness of different structures and abrasive resistance of composite coating were measured. The results show that the typical microstructure of LC WC7Co/Ti6Al4V composite coating can be classified into dissolved WC7Co composite structure and un-dissolved WC7Co structure. According to XRD results, there are Ti solid solution, W, TiC, VC, Co3W3C and secondary W2C in composite coating. The eutectic structure formed by the dissolved WC7Co particles consisted of W, W2C, TiC and β-Ti solid solution. The mean hardness of different structures exhibits a significant gradient distribution in composite coating. A reaction layer composed of TiC, W and W2C is also generated onto the interface between un-dissolved WC7Co particles and Ti6Al4V alloy matrix. The abrasive mechanisms of WC7Co/Ti6Al4V composite coating are mainly adhesive wear and oxidation wear during the dry sliding process.
Li-jing Yang,Shao-peng Wang,Pei Wang, et al. Microstructural evolution and abrasive resistance of WC7Co ceramic particle-reinforced Ti6Al4V composite coating prepared by pulse laser cladding[J]. Journal of Iron and Steel Research International, 2020, 27(2): 228-237.
2020, Vol. 27 
