复合涂层的组织与性能
( 1. 河海大学 材料科学与工程系， 南京 210098;
2. 东南大学 材料科学与工程系， 南京 210096)
摘 要: 利用等离子熔覆技术， 在廉价的碳钢表面原位合成了TiC/Ni基复合材料涂层。 借助金相显微镜、扫描电镜、 X射线衍射仪、 显微硬度计对复合涂层的组织、结构、 性能进行了测试。 结果表明： 当Ti+C含量为10%~20%时， 熔覆层成形良好, 与基体呈冶金结合， 无裂纹、 气孔等缺陷；熔覆层的组织为γ-Ni枝晶、 M23C6、 CrB及原位合成的TiC陶瓷颗粒， TiC大部分呈球状， 少量呈方块状， 尺寸为1~2μm， 靠近熔覆层底部的TiC颗粒比近表层的为小， 均弥散分布于熔覆层中； 熔覆层显微硬度达HV0.11000, 是碳钢基体的4倍。
关键字: 等离子熔覆； 原位合成； 组织； 复合涂层； TiC颗粒
TiC particle reinforced composite coating by plasma cladding
（ 1. Department of Materials Science and Engineering,
Hohai University, Nanjing 210098, China;
2. Department of Materials Science and Engineering,
Southeast University, Nanjing 210096, China）
Abstract: Plasma cladding technology was used for in-situ synthesis of TiC/Ni composite coating. The microstructure and properties of the coating were investigated by optical microscope, scanning electron microscope, X-Ray diffractometer, transmission electron microscope and microhardness tester. The results show that excellent bonding between the coating and the carbon steel substrate is ensured by the strong metallurgical interface, and the coating is uniform, continuous and almost defect-free when ［Ti+C］ is varied from 10% to 20% after ball milling. The microstructure of the plasma-cladded coating is mainly composed of γ-Ni dendrite, M23C6 , CrB and TiC ceramic particle which is synthesized in-situ. Most of TiC particles are spherical and a small fraction are blocky. TiC particle size is 1-2μm. The particles at the bottom are smaller than those near the top of the coating， and dispersivly distributed in the cladded coating. The maximum hardness of the coating is HV0.1 1000, and 4 times of the microhardness of the steel substrate
Key words: plasma cladding; in-situ synthesis; microstructure; composite coating; TiC particle
