等离子重熔处理对SPS烧结FeWB涂层组织及耐磨性影响  

Influence of plasma remelting on microstructure and wear resistance of in situ synthesized FeWB coatings prepared by spark plasma sintering

作　　者：王佳峰[1] 崔洪芝[1] 毕文彪 张新杰[1] 王明亮 WANG Jia-feng;CUI Hong-zhi;BI Wen-biao;ZHANG Xin-jie;WANG Ming-liang(School of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, Chin)

机构地区：[1]山东科技大学材料科学与工程学院

出　　处：《材料热处理学报》2018年第5期117-125,共9页Transactions of Materials and Heat Treatment

基　　金：国家高技术研究发展计划(863计划)项目(2015AA034404);国家自然科学基金(51772176);泰山学者攀登计划(tspd20161006)

摘　　要：采用SPS烧结工艺,以W、Fe和Fe-B合金粉为原料,在Q235基板表面制备FeWB涂层,并在不同电流下对预制的涂层进行重熔处理。借助X射线衍射仪、扫描电镜、显微硬度计和磨损试验机分析了FeWB涂层的显微组织结构、显微硬度和耐磨性。结果表明：未重熔SPS烧结涂层与Q235基板呈机械结合,涂层中存在大量的原料W及部分中间产物W2B、Fe7W6,只有少量FeWB生成,且组织偏聚严重、孔隙较多,导致其显微硬度较低且不均匀,耐磨性较差;经低电流（30 A）重熔,部分原料进一步转化为FeWB,缺陷有所减少;随着重熔电流增加（40 A和50 A）,涂层与Q235基板结合界面形成结合紧密的过渡层,呈冶金结合,原料基本完全转化为FeWB,并呈块状均匀分布在α-Fe基体中,组织结构更加致密,表现出较高的显微硬度,耐磨性显著增强,尤其40 A电流下重熔涂层表现出更加优异的耐磨性,其磨损量仅为未重熔SPS烧结涂层的17.4%。FeWB coatings were prepared on Q235 steel substrate by spark plasma sintering using W,Fe,and Fe-B alloy powder mixture as raw materials,and then the coatings were treated by plasma re-melting at different currents. Microstructure,microhardness and wear resistance of the FeWB coatings were investigated by means of X-ray diffraction,scanning electron microscopy,microhardness tester and wear tester. The results show that the un-remelted SPS sintering coating is mechanically combined with the Q235 substrate. There are a large number of raw materials W and some intermediate products W2B and Fe7W6 in the coating. Only a small amount of FeWB is generated,and the microstructure is seriously segregated and the pores are more,resulting in low hardness and poor wear resistance. After remelting at low current（30 A）,some raw materials are further transformed into FeWB,and the defects are reduced. With the increase of remelting current（40 A and 50 A）,the interface between the coating and Q235 substrate forms a transition layer,which forms a metallurgical bond. The raw materials are completely transformed into FeWB, and distributed uniformly in the α-Fe matrix, the microstructure becomes denser,the coatings show higher microhardness,and the wear resistance is significantly enhanced. Especially,the remelting coatings exhibit better wear resistance at current of 40 A. The wear rate of the re-melted coating is only 17. 4% of that of the unremelted SPS sintering coating.

关 键 词：SPS烧结 等离子重熔 FeWB涂层 耐磨性 

分 类 号：TG174.44[金属学及工艺—金属表面处理]