重熔对NiCrBSi涂层组织及高温耐磨性能的影响  

Effect of Remelting on Microstructure and High Temperature Wear Resistance of NiCrBSi Coating

作　　者：董天顺[1] 李小兵[1] 李国禄[1] 王海斗[2] 刘明 周秀锴 DONG Tian-shun;LI Xiao-bing;LI Guo-lu;WANG Hai-dou;LIU Ming;ZHOU Xiu-kai(School of Materials Science and Engineering,Hebei University of Technology,Tianjin 300130,China;National Key Lab for Remanufacturing,Academy of Armored Forces Engineering,Beijing 100072,China)

机构地区：[1]河北工业大学材料科学与工程学院,天津300130 [2]陆军装甲兵学院装备再制造技术国防科技重点实验室,北京100072

出　　处：《表面技术》2018年第8期105-112,共8页Surface Technology

基　　金：国家自然科学基金(51675158;51535011);河北省自然科学基金(E2016202325);973计划(61328304)~~

摘　　要：目的改善Ni Cr BSi涂层的组织及高温耐磨性能。方法采用等离子喷涂在45号钢基体上制备Ni Cr BSi涂层,并用氩弧对其进行重熔处理。利用扫描电子显微镜、能谱仪和X射线衍射仪对喷涂层与重熔层的形貌、微观组织、成分与物相进行分析。采用显微硬度仪与纳米压痕仪测试涂层的硬度、弹性模量,并计算出涂层的断裂韧性。通过室温、300℃、500℃的摩擦磨损试验评价和比较喷涂层与重熔层的耐磨性能。结果重熔层各元素分布较均匀,主要由γ-(Fe,Ni)、Cr2B、Mn5Si2和α-Fe等物相组成。重熔层由喷涂层的层状结构转变为致密的铸态组织,孔隙率由7.2%降低至0.4%,重熔层与基体之间形成了冶金结合。涂层重熔后硬度由724HV降低至608HV,但是弹性模量与断裂韧性分别由161.15 GPa和0.63 MPa·m^(1/2)提高至195.92 GPa和7.18 MPa·m^(1/2)。结论重熔处理改善了涂层的组织,使得重熔层在室温、300℃、500℃的耐磨性能均优于喷涂层。随着温度的升高,喷涂层氧化脱落越来越严重,而重熔层无明显氧化脱落。The work aims to improve microstructure and high temperature wear resistance of NiCrBSi coating.NiCrBSi coating was prepared on 45#steel by plasma spraying,then the coating was remelted by argon arc.Morphology,microstructure,composition and phase of sprayed coating and remelted coating were analyzed by scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and X ray diffractometer(XRD).Hardness and elastic modulus of the coating were tested by microhardness tester and nano-indentor,and fracture toughness of the coating was calculated.Wear resistance of the sprayed coating and remelted coating was evaluated and compared by performing friction-wear test at room temperature,300℃and 500℃.Various elements of the remelted coating were uniformly distributed,and phase mainly consisted ofγ-(Fe,Ni),Cr2B,Mn5Si2 andα-Fe.Structure of the remelted coating transformed from layered structure of sprayed coating to compact cast structure,and porosity was reduced from 7.2%to 0.4%.Metallurgical bonding was formed between remelted coating and substrate.Hardness of the coating was reduced from 724HV to 608HV after remelting,while the elastic modulus of remelted coating was increased from 161.15 GPa to 195.92 GPa,and fracture toughness was increased from 0.63 MPa·m^1/2 to 7.18 MPa·m^1/2.Remelting treatment improves microstructure of the coating,wear resistance of the remelted coating is better than that of sprayed coating at room temperature,300℃and 500℃.Both oxidation and spalling of sprayed coating are increasingly severe with the increase of temperature,while the remelted coating is not subject to obvious oxidation and spalling.

关 键 词：NiCrBSi涂层 氩弧重熔 组织 力学性能 高温耐磨性能 

分 类 号：TG174.44[金属学及工艺—金属表面处理]