氩弧熔覆原位自生NbC增强镍基复合涂层分析

Analysis of in-situ NbC Reinforced Ni-based Composite Coating by Argon Arc Cladding

以碳粉、铌粉和Ni60A粉为原料,利用氩弧熔覆技术在Q345钢基材表面原位合成了NbC增强Ni基复合涂层,应用SEM,XRD对涂层的显微组织和物相进行了分析,并测试了涂层显微硬度和常温耐磨性。结果表明,复合涂层与基体界面无气孔、裂纹,呈冶金结合;涂层组织由γ-Ni,Cr23C6和NbC颗粒相组成。涂层的显微硬度HV0.2达到1000,较基体提高3倍左右;耐磨性较基体Q345钢提高近11倍。

NbC reinforced Ni-based composite coating was fabricated on the surface of Q345 steel by means of argon arc cladding technique with powder of C, Nb and Ni60A. Microstructure and phase constituent of the coating were observed by SEM (scanning electron microscope) and XRD (X-ray diffraction), meanwhile, micro-hardness and ambient wear resistance of the coating were measured. It is found that absence of gas hole and crack in interface of composite coating with the matrix can be observed, exhibiting desirable metallurgical bonding. Microstructure of the composite coating is composed of γ-Ni, Cr23C6 and NbC. Micro-hardness of the composite coating reaches up to 1000, increased by approximately three times compared with that of the matrix alloy, and wear resistance is increased by approximately 11 times compared with the matrix.