原位自生TiC-TiB2增强Fe基复合涂层的凝固特性及形成机理  

Solidification characteristic and formation mechanism of in-situ synthesized TiC-TiB_2 reinforced Fe-matrix composite coating

作　　者：王振廷[1,2] 周晓辉[2] 张显友[1] 郑维[2] 

机构地区：[1]哈尔滨理工大学材料科学与工程博士后流动站,黑龙江哈尔滨150080 [2]黑龙江科技学院材料科学与工程学院,黑龙江哈尔滨150027

出　　处：《材料热处理学报》2009年第3期154-159,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金资助项目(50075085);黑龙江省教育厅科学技术研究项目(11511353)

摘　　要：以Ti、B4C和Fe粉为原料,利用氩弧熔敷技术在Q235钢基体表面制备出原位自生TiC-TiB2增强Fe基复合涂层。利用扫描电镜(SEM)、X射线衍射仪(XRD)对涂层的显微组织进行了分析。并分析了TiC和TiB2颗粒的形成机理和氩弧熔池的凝固特性。实验结果表明:熔敷层组织为TiC和TiB2弥散分布在α-Fe中,熔敷层与基体呈冶金结合,无裂纹、气孔等缺陷;涂层中TiC和TiB2的体积分数约为68%。形成机理主要是以固态扩散机制为主,TiC以小颗粒状和花瓣状先析出,后析出的TiB2多以六边形、短棒状存在,TiB2的组织比较粗大,TiC颗粒比较细小,TiB2的含量大于TiC含量。Fe based composite coating reinforced by in-situ synthesized TiC and TiB2 particulates was prepared on the surface of Q235 steel by means of argon are cladding（AAC） using Ti, B4C and Fe powders as raw materials. The microstructure were investigated by means of scanning electron microscopy（SEM） and X-ray diffraction analysis （XRD）. The formation mechanism of TiC and TiB2 particulates was studied, and the solidification characteristic of melting-pool of argon arc cladding was examined. The results show that TiC and TiB2 particles distribute in α-Fe dispersively. Excellent metallurgical bonding between the coating and the Q235 steel substrate forms and no defect such as flaw and pores is observed. Solid-state diffusion is the mechanism governing the synthesis process. It is seen that TiC is the first phase formed in granule and petal shapes, and then TiB2 in hexagon and rod shape precipitates. The size of TiB2 particles is larger than TiC particles. The content of TiB2 is higher than that of TiC in the coating. The volume percent of TiC-TiB2 is about 68% .

关 键 词：氩弧熔敷 TIC-TIB2 形成机理 凝固特性 

分 类 号：TG174.44[金属学及工艺—金属表面处理]