Ti6Al4V合金激光熔覆NiMoSi复合涂层的高温抗氧化性能  

High Temperature Oxidation Resistance of NiMoSi Composite Coatings on Ti6Al4V Alloy by Laser Cladding

作　　者：柯金 刘秀波 庄宿国 杨霞辉 梁珏 罗迎社[1] KE Jin;LIU Xiubo;ZHUANG Suguo;YANG Xiahui;LIANG Jue;LUO Yingshe(Hunan Province Key Laboratory of Engineering Rheology,Central South University of Forestry &Technology,Changsha410004,China;Xi'an Aerospace Propulsion Institute,Xi'an 710049,China;National United Engineering Laboratory for Advanced Bearing Tribology,Henan University of Science and Technology,Luoyang 471003,China;Hunan Province Key Laboratory of Materials Surface/Interface Science &Technology,Central South University of Forestry &Technology,Changsha410004,China)

机构地区：[1]中南林业科技大学工程流变学湖南省重点实验室,长沙410004 [2]河南科技大学高端轴承摩擦学技术与应用国家地方联合工程实验室,洛阳471003 [3]中南林业科技大学材料表界面科学与技术湖南省重点实验室,长沙410004 [4]西安航天动力研究所,西安710049

出　　处：《中国表面工程》2018年第6期109-117,共9页China Surface Engineering

基　　金：国家自然科学基金(U1737112);湖南省自然科学基金(2018JJ2677);河南科技大学高端轴承摩擦学技术与应用国家地方联合工程实验室开放基金(201803)~~

摘　　要：为提高Ti6Al4V合金的高温抗氧化性能,以Ni-48%Mo-32%Si混合粉末为原料,采用激光熔覆技术在Ti6Al4V合金表面制备复合涂层,分析涂层物相、组织结构、高温抗氧化性能及抗磨损性能,并讨论相关机理。结果表明:复合涂层中无裂纹,与基体实现了良好的冶金结合;硬质相Ti5Si3、MoSi2和Mo5Si3均匀分布于基体α-Ti、NiTi中。经恒温800℃氧化100 h后,复合涂层的氧化膜主要由TiO2、SiO2和NiO组成,结构连续致密,表现出较好的高温抗氧化性能。而Ti6Al4V合金氧化膜主要为疏松TiO2,表面氧化严重;氧化后,复合涂层和基体的单位面积增重分别为1.31和23.38 mg/cm2;复合涂层和基体的摩擦因数分为0.44和0.52、磨损率分别为16.2×10-5和22.6×10-5mm3/Nm,复合涂层的摩擦学性能亦有明显提高。In order to enhance the high-temperature oxidation resistance of Ti6Al4 V alloy,Ni-48% Mo-32% Si precursor mixed powders were adopted to prepare the composite coatings by laser cladding.The phase composition,microstructure,high temperature oxidation resistance and wear resistance of the composite coatings were analyzed,and the corresponding mechanisms were discussed.Results show that the composite coatings with no cracks have metallurgical bonding with the substrates.The enhanced phases composed of primary Ti5Si3/MoSi2/Mo5Si3 are well-distributed in the inter-primary α-Ti and NiTi intermetallic compounds matrix.Relatively dense oxide films consisting of TiO2/SiO2/NiO are formed on the surface of the composite coating,indicating good high-temperature oxidation resistance after isothermal oxidation test at 800 ℃ for 100 h.While the oxide films of Ti6Al4 V alloy are mainly porous TiO2,and the surface is severely oxidized.The weight gain per unit area of the composite coatings and the substrate after oxidation is 1.31 and 23.38 mg/cm2.While the friction coefficients of the composite coatings and the substrate are 0.44 and 0.52,and their wear rates are 16.2×10^-5 and 22.6×10^-5mm^3/Nm.This means that tribological properties of the composite coatings are also obviously improved.

关 键 词：激光熔覆 NiMoSi 复合涂层 高温氧化 耐磨 

分 类 号：TG174.44[金属学及工艺—金属表面处理]