Ni3Al（Cr）合金室温干滑动摩擦磨损性能研究

Friction and wear properties of Ni3Al（Cr） alloys at room temperature

采用真空电弧熔炼法制备添加不同Cr含量的Ni3Al(Cr)合金,观察其组织和力学性能变化,以Si3N4为对磨副,探究不同载荷下Ni3Al(Cr)合金的摩擦磨损机制.利用扫描电子显微镜拍摄材料的组织以及磨痕、磨痕截面形貌,测量磨痕截面显微硬度的变化.研究结果表明:随着Cr含量的增加,Ni3Al(Cr)材料的硬度,摩擦系数和磨损率不断增加,Ni3Al-12Cr合金的摩擦磨损性能较好.随着载荷的增加,Ni3Al(Cr)合金的摩擦系数略有减小,磨损率不断升高;Ni3Al合金随载荷的增加磨损机制由磨粒磨损和氧化磨损转变为疲劳磨损,剧烈的剥层磨损为主,并伴有氧化磨损,而Ni3Al-12Cr合金在不同载荷下磨损机制主要为磨粒磨损和氧化磨损.

Ni3Al intermetallic with different Cr contents was successfully produced by vacuum arc melting.The change of microstructure and mechanical property were observed.Dry sliding tribological tests of the Ni3Al alloys were undertaken against Si3N4.In order to study the wear mechanism,the worn surface and wear scar section of the alloys were detected by using scanning electron microscopy(SEM).Vickers hardness of the wear scar section was also measured.The results showed that the hardness,friction coefficient and wear rate of the alloys increased with the increase of Cr content.The Ni3Al-12Cr alloy obtained the best wear resistance property compared with other three alloys.Besides,friction coefficient declined and wear rate increased with the increase of load.It was found that the dominant wear mechanism of Ni3Al alloy changed from abrasive wear and oxidative wear to fatigue wear,severe layer wear accompanied by oxidation wear.The wear mechanism of Ni3Al-12Cr alloy was mainly abrasive wear and oxidative wear.