摘要
采用真空熔烧的方法在45钢表面制得Ni-WC-CeO2复合涂层试样,利用光学显微镜、扫描电镜和能谱仪分析了CeO2添加量对涂层纵截面的微观组织形貌的影响,分析了WC的形貌和分布及熔烧带处的元素扩散情况。结果表明:CeO2的加入改善了涂层的组织,使其更加细小、均匀,消除了针状相;在CeO2添加量为0.75%时涂层和基体之间的互熔结合最好,涂层中的气孔、裂纹等缺陷最少;CeO2对合金元素原子的扩散有明显的促进作用,结合处主要以Fe、Ni扩散为主;CeO2改变了硬质相WC在涂层中的形貌和分布形式,使其变得细小、均匀、分散,促进了涂层中Ni基合金和WC之间的扩散,使WC在涂层中主要以4种形貌存在:条状、白色块状、灰色块状和灰色球状。
Ni-WC-CeO2 composite coating on 45 steel was made by the way of vacuum fusion sintering.The influence of CeO2 content on microstructure morphology of the coatings on longitudinal section was investigated.The shape and distribution of WC and the element diffusion in molten zone were analyzed by optical microscope,SEM and energy-dispersive spectrometer.The results show that microstructure of the coatings is finer and more homogeneous and the needle-shaped phase is erased by adding CeO2.When the content of CeO2 is 0.75%,the metallurgical bonding of coating and matrix is the best,and the defects such as porosity,crack and so on is the least.Promotive action of CeO2 on diffusion of alloying elements is obviously,the main diffusion on the bonded zone is Fe and Ni diffusion.By introducing CeO2,the shape and distribution of hard phase WC in the coating are improved,it is fine,homogeneous and dispersive which exists four forms including strip,white massive,gray massive and gray globosity.
出处
《金属热处理》
CAS
CSCD
北大核心
2012年第11期59-63,共5页
Heat Treatment of Metals
基金
辽宁省教育厅项目(2008331)
