低压冷喷涂热处理复合处理制备Ni_(2)Al_(3)金属间化合物涂层及其滑动磨损特性研究

Study on Ni_(2)Al_(3) Intermetallic Compound Coating Prepared by Low Pressure Cold Spraying and Heat Treatment and Its Sliding Wear Performance

为制备出以Ni_(2)Al_(3)为主相的金属间化合物涂层,将Ni粉、Al粉和Al_(2)O_(3)粉按质量比20∶6∶5混合均匀,利用低压冷喷涂方法将混合粉体喷涂到45钢基体表面,制备Ni-Al预涂层,再将预涂层在520℃氩气环境下保温12 h,采用X射线衍射(XRD)和扫描电镜(SEM)对涂层组织和物相进行了分析与表征,测试了涂层的结合力和滑动摩擦磨损特性。结果表明:预涂层经热处理转变为Ni_(2)Al_(3)金属间化合物涂层后,表现出良好的减摩、耐磨性能。涂层中Ni和Al固相转变为金属间化合物的驱动力是热处理提供的热能和粉体强烈塑性变形后的形变能的共同作用。

For preparing an intermetallic compound coating with Ni_(2)Al_(3) as the main phase,the Ni,Al and Al_(2)O_(3) powders were mixed uniformly based on a mass ration of 20∶6∶5,and the mixed powders were sprayed onto the 45 steel surface to form a Ni⁃Al pre⁃coating by low pressure cold spraying method.Subsequently,the Ni⁃Al pre⁃coating was kept in an argon atmosphere at 520℃for 12 h.The morphology and phase structure of the as⁃prepared coating were analyzed and characterized by X⁃ray diffraction(XRD)and scanning electron microscope(SEM).In addition,the bonding force as well as the sliding friction and wear performances of the coating were tested.Results showed that after thermal treatment,the pre⁃coating changed into a Ni_(2)Al_(3) intermetallic compound coating,which presented superior anti⁃friction and wear⁃resisting properties.The driving force for the transformation of Ni and Al solid phases into intermetallic compound was the combined effect of thermal energy provided by heat treatment and deformation energy of the powders resulting from strong plastic deformation.