真空熔覆WC/h-BN/Ni复合涂层的组织及物相分析  

Microstructure and phase analysis of WC/h-BN/Ni composite coating fabricated by vacuum cladding

作　　者：王军军 杨贵荣[1] 宋文明 李亚敏[1] 马颖[1] WANG Jun-jun;YANG Gui-rong;SONG Wen-ming;LI Ya-min;MA Ying(State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;Machinary Industry Shanghai Lanya Petrochemical Equipment Inspection Ltd,Lanzhou 730070,China)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州730050 [2]机械工业上海蓝亚石化设备检测所有限公司,甘肃兰州730070

出　　处：《材料热处理学报》2022年第9期165-175,共11页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51765035,51205178);辽宁省航发材料摩擦学重点实验室开放课题(LKLAMTF202201)。

摘　　要：采用真空熔覆技术在45钢表面制备了WC/h-BN/Ni基复合涂层,并通过扫描电镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)等观察并分析了复合涂层的微观组织形貌和物相组成。结果表明:复合涂层形成了不同微观组织特征的区域,从表面到基体依次为表层区、复合区、过渡区、扩散熔合区及扩散影响区,主要相组成包括γ-Ni固溶体、FeNi_(3)、Cr_(7)C_(3)、Cr_(23)C_(6)、WC、W_(2)C、Ni_(3)Si、Ni_(3)B、CrB、Cr_(2)B、BN和Ni_(2.9)Cr_(0.7)Fe_(0.36)等。复合涂层与基体的界面区域因元素的互扩散而形成了一条厚度约为16μm的扩散熔合带,熔合带中没有硬质相;靠近基体一侧的扩散影响区由大量珠光体组成,连接复合区的过渡层中分布有多种形式的固溶强化相及少量的弥散相;表层区因受粉末颗粒本身及温度等影响,形成了较多的多由Cr_(7)C_(3)、Cr_(23)C_(6)等化合物组成的针状物相及不规则孔隙。随着温度的升高复合涂层中烧结颈不断长大,使得其中的孔隙从闭合球化状态逐渐收缩直至消失,进而形成组织致密的复合涂层。WC/h-BN/Ni-based composite coating was fabricated on 45 steel substrate by vacuum cladding technology,and microstructure and phase composition of the composite coating were observed and analyzed by means of scanning electron microscopy(SEM),energy dispersive spectrometer(EDS)analysis and X-ray diffractometer(XRD).The results show that the composite coating has formed regions with different microstructure characteristics,from the surface to the substrate,it is divided into surface zone,composite zone,transition zone,diffusion fusion zone and diffusion affected zone.The main phase composition includesγ-Ni solid solution,FeNi_(3),Cr_(7)C_(3),Cr_(23)C_(6),WC,W_(2)C,Ni_(3)Si,Ni_(3)B,CrB,Cr_(2)B,BN and Ni_(2.9)Cr_(0.7)Fe_(0.36) phases.A diffusion fusion zone with thickness of about 16μm is formed at the interface between the composite coating and the substrate due to the mutual diffusion of elements,and there is no hard phase in the fusion zone.The diffusion affected zone near the substrate side is composed of a large amount of pearlite,and there are many forms of solid solution strengthening phase and a small amount of dispersed phase in the transition layer connecting the composite zone.Due to the influence of the powder particles themselves and the temperature,the surface layer is formed many acicular phases which composed of Cr_(7)C_(3),Cr_(23)C_(6) and other compounds and irregular pores.With the increase of temperature,the sintered neck in the composite coating grows continuously,which makes the pores shrink gradually from the closed spheroidizing state to disappear,and then forms a composite coating with dense structure.

关 键 词：镍基合金 真空熔覆 复合涂层 孔隙 致密化 冶金结合 

分 类 号：TG174.44[金属学及工艺—金属表面处理]