Improving high-temperature wear resistance of NiCr matrix self-lubricating composites by controlling oxidation and surface texturing  

作　　者：Xuan Kong Wenyao Sun Qunchang Wang Minghui Chen Tao Zhang Fuhui Wang 

机构地区：[1]Shenyang National Laboratory for Materials Science,Northeastern University,Shenyang 110819,China

出　　处：《Journal of Materials Science & Technology》2022年第36期253-263,共11页材料科学技术（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.51871051)。

摘　　要：Self-lubricating composites(SLCs)are widely used in the fields of aerospace and marine,but the conventional NiCr matrix SLCs with sulfide as solid lubricant often suffer from low wear resistance at high temperatures.In view of its high affinity with oxygen and also the high oxidation rate,appropriate amount of nano Ti was added to NiCr-WS_(2)composites prepared by spark plasma sintering(SPS)to adjust the oxidation behavior and surface texture.When exposed to high temperature,Ti was preferentially oxidized in comparison to Ni and Cr,resulting in abundant TiO_(2)protrusions and microdimples on the surface,i.e.in situ surface texturing.Besides,TiO_(2)was of high chemical activity and readily to react with other oxide debris during high temperature sliding process to form compounds of NiTiO_(3)and CrTi_(2)O_(5).The high chemical activity of oxide debris that was conducive to sintering,combining with the special surface texture that stores as many wear debris as possible,promoted the rapid formation of a protective glaze layer on the sliding surface.The NiCr-WS_(2)-Ti composite exhibited low friction coefficient but high wear resistance at elevated temperatures.Especially at 800℃,it presented a wear rate of as low as(2.1±0.3)×10^(-5)mm^3N-1m^(-1),accounting for only 2.7%of that of NiCr-WS_(2)composite.

关 键 词：Self-lubricating composites High temperature oxidation Glaze layer Surface texturing 

分 类 号：TB33[一般工业技术—材料科学与工程]