热处理对NiCr/Cr_3C_2-WS_2复合涂层组织与性能的影响  

Effects of heat treatment on microstructure and performance of NiCr/Cr_3C_2-WS_2 composite coatings

作　　者：孟祥军[1] 刘秀波[1] 刘海青[1] 郑晨[1] 孙承峰[1] 王明娣[1] 齐龙浩[2] 

机构地区：[1]苏州大学机电工程学院,江苏苏州215021 [2]清华大学新型陶瓷与精细工艺国家重点实验室,北京100084

出　　处：《材料热处理学报》2013年第S2期188-193,共6页Transactions of Materials and Heat Treatment

基　　金：江苏省自然科学基金(BK20131155);苏州市科技计划项目(SYG201349;SYG201233);江苏省高校自然科学基金(11KJB460008);国家自然科学基金(51205266)

摘　　要：为了研究激光熔覆NiCr/Cr3C2-WS2高温耐磨自润滑复合涂层组织的高温稳定性,对所制备的复合涂层在600℃下分别保温10 h、30 h、50 h,采用XRD、SEM、EDS等手段对热处理前后复合涂层的显微组织进行分析,并分别测试了热处理前后复合涂层的显微硬度及600℃下的滑动磨损性能。结果表明:热处理前后复合涂层物相基本相同,主要为:γ-(Fe,Ni)/Cr7C3共晶相、Cr7C3硬质相、CrS/WS2润滑相。随着保温时间的延长,由于γ-(Fe,Ni)/Cr7C3共晶相的溶解,其体积分数逐渐降低,并且保温50 h后共晶相大部分溶解,Cr7C3相出现断裂造粒现象,复合涂层的硬度有所降低。热处理对复合涂层的摩擦学性能影响不大。The NiCr/Cr3C2-WS2 high-temperature self-lubrication wear-resistant composite coatings were fabricated on substrate of austenitic stainless steel by laser cladding. The high-temperature structural stability of the composite coatings was evaluated by aging at 600 ℃ for 10 h,30 h,50 h,respectively,and the microstructure of the as-laser clad and aged coatings was examined by means of XRD,SEM,EDS. The sliding wear resistance of the as-laser and aged coatings was evaluated at 600 ℃. The results show that the γ-(Fe,Ni)/Cr7C3 eutectic phase,Cr7C3 hard phase and CrS/WS2 phase all exist in the as-laser clad and aged coatings. The volume fraction of eutectic phases reduces gradually with the increasing of aging time due to their dissolution. The microhardness of the aged coating decreases slightly after aging at 600 ℃ for 50 h due to the dissolution of the eutectic phases and notable breaking or granulation of the Cr7C3 phases aging for 50 h,but the fractional properties are not significantly affected by heat treatment.

关 键 词：激光熔覆 复合涂层 热处理 显微结构 性能 

分 类 号：TG174.44[金属学及工艺—金属表面处理]