TC4合金表面双阴极等离子溅射沉积NbTiN_(2)涂层的摩擦磨损性能

Friction and Wear Properties of Double Cathode Plasma Sputtering Deposited NbTiN_(2) Coating on TC4 Alloy Surface

采用双阴极等离子溅射沉积技术在TC4合金表面制备了NbTiN_(2)涂层,研究了涂层的物相组成、微观形貌、硬度、与基体的结合情况以及摩擦磨损性能。结果表明:NbTiN_(2)涂层具有很强的(220)晶面择优取向特点;涂层表面质量良好,无明显缺陷,厚度约为10μm,平均硬度为2 478.46 HV,约为基体的6倍,涂层划痕试验的临界载荷为68.5 N,涂层与基体结合良好;在2~5 N载荷、室温下涂层的摩擦因数低于基体,磨痕比基体窄,磨损率比基体低一个数量级,涂层的主要磨损机制是疲劳磨损;500℃下涂层的摩擦因数较室温高,磨痕更窄更浅,磨损率较低,磨损机制为黏着磨损和氧化磨损,涂层表现出更好的耐磨性能。

NbTiN_(2)coating was prepared on TC4 alloy surface by dual cathode plasma sputtering deposition. The phase composition, microstructure, hardness, adhesion to matrix and friction and wear properties of the coating were studied. The results show that the NbTiN_(2)coating had strong(220) preferred orientation. The coating had good surface quality, no obvious defects and a thickness of about 10 μm. The average hardness of the coating was 2 478.46 HV, about 6 times that of the matrix, and the critical load of coating in scratch test was 68.5 N, indicating that the coating was well combined with the matrix. The friction coefficient of the coating was lower than that of the matrix under the load of 2-5 N at room temperature;the wear scar was narrower than that of the matrix, and the wear rate of the coating was one order of magnitude lower than that of the matrix;the main wear mechanism of the coating was fatigue wear. At 500 ℃, the friction coefficient was higher than that at room temperature, and the wear scar of the coating was narrower and shallower;the wear rate was lower, and the wear mechanism was adhesive wear and oxidation wear, indicating the coating had better wear resistance.