CTC_P/NiCrBSi局域化增强耐热钢基复合材料的界面及其高温磨损性能  

Interface Characteristics and High Temperature Wear Properties of Refractory Steel Matrix Composite Reinforced by Zoning CTC_P/NiCrBSi

作　　者：侯书增 鲍崇高[2] 付鸽 Hou Shuzeng;Bao Chonggao;Fu Ge(Sichuan University of Science & Engineering, Zigong 643000, China;State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China)

机构地区：[1]四川理工学院,四川自贡643000 [2]西安交通大学金属强度国家重点实验室,陕西西安710049

出　　处：《稀有金属材料与工程》2019年第7期2364-2370,共7页Rare Metal Materials and Engineering

基　　金：自贡市重点科技计划项目(2017XC21);四川理工学院人才引进项目(2015RC05);西华大学汽车高性能材料及成形技术省高校重点实验室项目(szjj2015-092)

摘　　要：以表面改性的铸造碳化钨颗粒(CTCP)为增强体,以NiCrBSi合金为粘结相,以耐热钢为基板采用真空熔烧工艺制备了一种CTCP/NiCrBSi局域化增强耐热钢基复合材料。观察分析了复合材料的界面特征及其形成机理,研究了复合材料在25~800℃下的磨损性能,并讨论了复合材料的磨损机理。结果表明,复合材料增强区域组织致密、CTCP分布均匀,增强区域与耐热钢基板之间的界面由CTCP分解区,γ-Ni等温凝固区和富含(Fe,Cr)-B的扩散影响区3个部分构成;在试验温度范围内,复合材料的磨损率都小于耐热钢的磨损率,复合材料的磨损率和相对耐磨性都随着试验温度的升高呈现先减小后增大的趋势,800℃时复合材料的相对耐磨性最高,达到耐热钢的1.8倍;在25~600℃时,复合材料的磨损机理主要是微观切削、塑变疲劳断裂、CTCP表面由磨料碾压刮擦导致的疲劳剥落和CTCP因NiCrBSi支撑不足导致的折断或脱落,在600~800℃时,复合材料的磨损机理主要是微观切削和氧化与磨损的交互作用。Using surface-modified cast tungsten carbide particles(CTCP)as reinforcement,NiCrBSi alloy as binder phase and refractory steel as substrate,refractory steel matrix composite reinforced by zoning CTCP/NiCrBSi was prepared by vacuum fusion sintering.Composite interface was observed and its formation mechanism was analyzed.Wear behaviors of the composite in the range of 25~800°C were studied.Wear mechanisms of the composite were also discussed.The results show that the structure is compact and the CTCP are evenly distributed in CTCP/NiCrBSi area of the composite;the interface between CTCP/NiCrBSi area and refractory steel substrate is composed of three parts:CTC_P dissolution zone,γ-Ni isothermal-solidification zone and element spread influence zone rich in(Fe,Cr)-B;within the test temperature range,the wear rate of the composite is less than that of refractory steel and both the wear rat e and the relative wear resistance of the composite show the trend of decreasing and then increasing with the increase of the test temperature;the relative wear resistance of the composite at 800°C is the highest,reaching 1.8 times that of refractory steel;in the range of 25~600°C,the wear mechanisms of the composite are mainly micro-plowing,fatigue fracture induced by plastic deformation,CTCP surface fatigue fracture caused by abrasive rolling and scratching,CTCP brokenness or shedding due to insufficient NiCrBSi support;in the range of 600~800°C,the wear mechanisms of the composite are mainly micro-plowing and mutual promotion of oxidation and wear.

关 键 词：金属基复合材料 高温磨损 局域化增强 铸造碳化钨 

分 类 号：TB333[一般工业技术—材料科学与工程]