原位合成TiC-M_7C_3金属复合涂层

In-situ Synthesis of TiC-M_7C_3 Metal-ceramics Composite Coating

为提高钢基材的耐磨性能,采用等离子堆焊技术,制备了原位自生M7C3-TiC增强铁基堆焊层。利用金相显微镜、扫描电镜、X射线衍射仪及显微硬度计对堆焊层的组织和性能进行了测试。结果表明:堆焊层与基体之间形成了良好的冶金结合;堆焊层表层组织由马氏体、(Fe,Cr)7C3和TiC构成;初生(Fe,Cr)7C3呈六边形,晶粒尺寸较大,均匀弥散分布在堆焊层中,TiC颗粒呈开花状、立方体或团聚状;堆焊层硬度从基体到表面呈合理的梯度分布,较基体有显著提高。

In order to improve the wear resistance of steel components, the in-situ MTC3-TiC ceramic phases reinforced Fe-based composite coating was produced by plasma transferred arc weld-surfacing process （PTA）. The microstructure and properties were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction and microhardness meter. The results show that the substrate and coating form good metallurgical bonding. The microstructure of the coating consists of martensite, （Fe, Cr）7C3 and TiC. The primary hexagonal （Fe, Cr）7C3 with larger size presents dispersively and evenly distributes in the coating; the fine TiC particles are flower-like, cubic or agglomerated shape. The microhardness of the coating, which is enhanced by MTC3-TiC particles, is much greater than that of the substrate.