以WC涂层在飞机起落架的应用作为研究背景，对300 M超高强钢基体上电镀硬铬和超音速火焰喷涂WC-17Co和WC-10Co4Cr涂层的疲劳及与Al—Ni—Bronze合金的摩擦磨损性能进行了研究。结果表明，有WC涂层300 M钢的疲劳寿命与无涂层300 M钢的疲劳极限和过载下的疲劳寿命相当，WC涂层对300 M钢的疲劳寿命不会产生不良影响；而电镀硬铬使300 M钢的疲劳极限降低120 MPa，疲劳寿命则降低70 %～90 %。疲劳失效分析表明， WC涂层中的疲劳裂纹在界面上发生偏斜，转向沿界面扩展，因此对基体的疲劳寿命没有影响；而电镀硬铬中的的疲劳裂纹扩展到基体表面，显著降低基体的疲劳寿命。10#航空液压油润滑下涂层与Al—Ni—Bronze合金的摩擦磨损表明，与电镀硬铬对磨时，Al—Ni—Bronze合金发生明显的磨损，同时因质量转移而导致电镀硬铬的质量显著增加；而WC涂层仅略有失重，相应地Al—Ni—Bronze合金的失重仅为与电镀硬铬层磨损失重的1/50～1/100。WC涂层与Al—Ni—Bronze合金的磨损机理主要为磨粒磨损；电镀硬铬与Al—Ni—Bronze合金的磨损机理主要为黏着磨损。

Fatigue and friction and wear performances against Al—Ni—Bronze alloy for bare and coated 300 M steel were investigated with the application of WC coating into landing gear as background in this paper. The results indicated that both WC-17Co and WC-10Co4Cr coated 300 M steel exhibited comparable fatigue limit and cycles to fatigue failure with those of bare 300 M steel; while the fatigue limit and cycles to fatigue failure of 300 M steel were decreased by 120 MPa and 70 %~90 % respectively when 300 M steel was plated with chrome plating. The effect of coating on the fatigue property of 300 M steel was attributed to the propagation of fatigue crack in coating. Fatigue crack in WC coating deflected along the interface between WC coating and 300 M steel; while fatigue crack in chrome plating propagated into 300 M steel, provided as a sub-crack initiator and hastened the propagation of main fatigue crack in 300 M steel and finally led to the decrease of cycles to fatigue failure of 300 M steel. Friction and wear behaviors of coatings against Al—Ni—Bronze alloy lubricated by 10# aircraft hydraulic oil revealed that great volume loss was observed for Al—Ni—Bronze alloy and obvious mass gain was found for chrome plated 300 M steel when chrome plating was against Al—Ni—Bronze alloy; slight volume loss was obtained for WC coating, and the volume loss of Al—Ni—Bronze alloy against WC coating was only 1/50~1/100 of Al—Ni—Bronze alloy against chrome plating at all the three loads. The wear mechanism for WC coating and chrome plating against Al—Ni—Bronze alloy was respectively governed by abrasive wear and adhesive wear.