激光熔覆原位制备ZrC颗粒增强涂层的行为特征  

Behavior Characteristics of In-situ Formed ZrC Particle Reinforcement Composite Coating by Laser Cladding

作　　者：雍耀维 张翔[1] 傅卫[3] 邓琦林[1] 杨建国[1] Yong Yaowei;Zhang Xiangl;Fu Wei;Deng Qilin;Yang Jianguo(Shanghai Jiao Tong University, Shanghai 200240, China;Ningxia University, Yinchuan 750021, China;State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China)

机构地区：[1]上海交通大学,上海200240 [2]宁夏大学,宁夏银川750021 [3]哈尔滨工业大学先进焊接与连接国家重点实验室,黑龙江哈尔滨150001

出　　处：《稀有金属材料与工程》2018年第5期1625-1630,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51275303)

摘　　要：通过添加氧化锆和石墨的混合粉末到镍基合金粉末中,利用激光熔覆技术在中碳钢表面上制备了原位析出ZrC颗粒增强金属Ni基复合涂层。利用扫描电镜(SEM),能谱仪(EDS)和X射线衍射仪(XRD)对涂层的组织、物相和成分进行了观察、分析和探讨。对涂层内部的ZrC颗粒形貌、生成以及生长机理、分布特点进行了分析,探讨了颗粒分布对涂层硬度性能的影响。结果表明,ZrC颗粒在中上部分布较为均匀,主要以三角形和四边类似菱形和长轴形为主,颗粒在对流和界面斥力共同作用下发生的碰撞、烧结以及枝晶间的阻力是成形主因。由于ZrC颗粒以及内部碳化物如M_(23)C_6的生成分布,复合涂层的硬度得到了明显的提升,最终其硬度(HV_(0.2))可达7200 MPa。Mixed powders of zirconium dioxide and graphite were added into Ni-based alloy powder, and then the ZrC particles reinforced NiCrBSi composite coating was prepared on mild steel by laser cladding. Microstructure, phase and composition of the NiCrBSi＋Zr composite coating were characterized by scanning electron microscope （SEM）, energy dispersive spectrometer （EDS） and X-ray diffractometer （XRD）, respectively. The morphology, formation and growth mechanism and distribution of ZrC reinforcements were studied, and the hardness of the coating was investigated as well. The results show that ZrC reinforcements are uniformly distributed in the upper part and the middle part of the coating. The morphologies of ZrC are mainly triangle, quadrilateral similar to rhombus and long-bar shaped, which is attributed to obstruction from the interdendritic growth, collision and sintering caused by high convection and repulsion between solid-liquid interface in the molten pool. The hardness of the composite coating is improved by ZrC reinforcements and carbide such as M23C6. Therefore, the hardness （HV0.2） of the composite coating can reach 7200 MPa

关 键 词：原位生成 碳化锆(ZrC) 颗粒相 生长机制 

分 类 号：TG174.453[金属学及工艺—金属表面处理] TN249[金属学及工艺—金属学]