耐磨性能的影响
(南京航空航天大学 机电学院，南京 210016)
摘 要: 采用浆料包渗法，以Cr2O3 粉为渗Cr源，纯Al 粉为还原剂，NH4Cl为活化剂，Al2O3为惰性添加剂，蛋白质(鸡蛋清)为粘结剂，在纯Cu表面预先镀Ni，随后表面浆料包渗Cr、Al，制备Cr、Al共渗层；研究稀土氧化物CeO2含量对Cr、Al渗层显微组织和耐磨性能的影响。采用SEM和XRD测定渗层的表面形貌和结构。结果表明：添加稀土氧化物CeO2后，渗层表面显微组织产生明显变化，颗粒由大变小，渗层变致密，组织由单一的Ni(Cr、Al)固溶体转变为由Ni3Al相和固溶体混合组成；随着稀土氧化物CeO2含量的增加，固溶体中Cr含量先增后减，渗层的摩擦因数先降后升，最小摩擦因数为纯铜的1/3。
关键字: 纯铜；Cr2O3粉；CeO2；Cr-Al渗层；稀土氧化物；耐磨性
Cr-Al coating by slurry packing on copper
（College of Mechanical and Electrical Engineering, Nanjing University of
Aeronautics and Astronautics, Nanjing 210016, China）
Abstract:By a slurry pack cementation, with Cr2O3 as chromizing source, pure Al powders as reducers, NH4Cl as activator and albumen (egg white) as cohesive agent, electroplated specimens with a layer of electroplated nickel originally deposited on copper were chromized to prepare Cr-Al coating. The effects of CeO2 content on the microstructure and wear resistance of Cr-Al coating were studied. The surface morphology and structure of coating were examined by means of SEM and XRD. The results show that the grain of the coating becomes small, the coating becomes dense, the microstructure of coating changes from a solid solution of Cr and Al in nickel of single phase into the mixture of Ni3Al phase and a solid solution after adding CeO2 oxides; the Cr content in coating firstly increases and then decreases with the increase of CeO2 content, but the coefficient of friction of coating firstly decreases and then increases with the increase of CeO2 content, and the minimum value is 1/3 that of pure copper.
Key words: pure copper; Cr2O3 powder; Ce2O; Cr-Al coating; rare earth oxide; wear resistance
