固体润滑剂WS_2含量对钛合金表面激光熔覆NiCr/Cr_3C_2-WS_2层组构及性能的影响  

Effect of Solid Lubricant Tungsten Disulfide on Microstructure and Wear Resistance of Laser Cladding NiCr/Cr_3C_2-WS_2 Coatings on Titanium Alloy Substrate

作　　者：罗健[1] 刘秀波[1] 相占凤 任佳[1] 刘海青[1] 陈瑶[1] 吴少华[2] 石皋莲[2] 

机构地区：[1]苏州大学机电工程学院,江苏苏州215006 [2]苏州工业职业技术学院,江苏苏州215104

出　　处：《材料保护》2015年第5期13-16,6-7,共4页Materials Protection

基　　金：江苏省自然科学基金(BK20141194;BK20131155);苏州市科技计划项目(SYG201349);江苏省材料摩擦学重点实验室开放基金(Kjsmcx201301)资助

摘　　要：为拓宽钛合金表面耐磨自润滑复合涂层的研究领域,采用10kWCO2激光器,在Ti-6Al-4V钛合金表面熔覆制备了4种不同WS2含量(0,10%,20%,30%)的NiCr/Cr3C2-WS2层。利用扫描电镜(SEM)、能谱分析仪(EDS)和X射线衍射仪(XRD)等分析了涂层组织、相组成以及磨损形貌,利用MH-5半自动显微硬度计和HT-1000型球-盘式高温摩擦磨损试验机测试了涂层的硬度和摩擦磨损性能,对比研究了4种NiCr/Cr3C2-WS2熔覆层的微观组织和在室温、载荷为6N条件下的摩擦学性能。结果表明:未添加WS2熔覆层的组织主要是由γ-NiCrAlTi,TiC和α-Ti相组成,添加WS2熔覆层的组织主要是由γ-NiCrAlTi,TiC,TiWC2,α-Ti,Ti2CS和CrS相组成;未添加WS2的熔覆层的平均显微硬度最高,达到1149HV2N,是钛合金基体显微硬度的3.2倍。添加WS2固体自润滑剂改善了熔覆层摩擦学性能,其中添加30%WS2的熔覆层摩擦学性能最佳。A 10 kW CO2 laser was performed to prepare Ni Cr / Cr3C2-WS2 laser cladding coatings with different contents of WS2( 0,10%,20%,30%; mass fraction,the same hereafter) on Ti-6Al-4V alloy substrate. The cross-sectional microstructure,phase composition and worn surface morphology of the composite coatings were analyzed by scanning electron microscopy,energy dispersive spectrometry and X-ray diffracto-meter. The microhardness profile of the coatings along the depth direction was measured with a microhardness tester,and their friction and wear behavior under dry sliding against Si3N4 ceramic ball at a normal load of 6 N in ambient air was evaluated with an HT-1000 ball-on-disc friction and wear tester. It was found that the as- fabricated Ni Cr / Cr3C2 laser cladding coating without WS2 mainly consisted of γ-Ni Cr Al Ti,Ti C and α-Ti,while the Ni Cr / Cr3C2-WS2 laser cladding coatings mainly consised ofγ-Ni Cr Al Ti,Ti C,Ti WC2,α-Ti,Ti2 CS and Cr S. In the meantime,Ni Cr / Cr3C2 laser cladding coating without WS2 exhibited the highest average microhardness of 1 149 HV2 N,and it was 3. 2times as much as that of the Ti alloy substrate. Moreover,introducing solid lubricant WS2 helped to improve the wear resistance of Ni Cr / Cr3C2 laser cladding coating,and the coating containing30% WS2 exhibited the best wear resistance.

关 键 词：激光熔覆 NiCr/Cr3C2-WS2涂层 固体润滑剂WS2 组织结构 硬度 摩擦学性能 钛合金 

分 类 号：TG174.4[金属学及工艺—金属表面处理]