(1. 南京航空航天大学 材料科学与技术学院，南京 210016;2. 南京理工大学 材料科学与工程系，南京 210094)
摘 要: 采用双层辉光等离子表面合金化技术对Ti2AlNb基合金进行表面渗Cr处理，结果表明：经过离子渗铬处理后可获得约25 μm的表面合金层；渗层中Cr含量随渗层深度呈梯度变化，且由于原子扩散能力的差异，在渗层的不同区域形成不同相，结合XRD和XPS分析技术，证实表层以含Cr2Nb的Laves相和Al8Cr5相为主； 渗层硬度值由外层的HV0.11 125逐渐过渡到基体的HV0.1400左右；渗Cr处理后合金室温摩擦因数由原来的0.24降低到0.15，由于硬质Cr2Nb和Al8Cr5相起到支撑载荷的作用，降低粘着磨损，室温磨损率降低60%以上；高温条件下由于氧化和摩擦磨损的共同作用，摩擦因数变化不大，磨损率降低20%。
关键字: Ti2AlNb基合金；双辉等离子表面合金化；摩擦；磨损
（1. School of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;2. Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China）
Abstract:Surface chromising was performed on the Ti2AlNb-based (O phase) alloy using the double glow plasma process to enhance its wear-resistance. The results show that the thickness of alloying layer is approximately 25 μm by surface plasma chromising. The content of chromium of the alloying layer distributes gradually. The various phases distribute in different areas due to the diffusion of atomics under high temperature. The Cr2Nb with Laves phase and Al8Cr5 phases with high hardness are in the sub-surface while new disorder O-phases (Ti 25.36Al 18.44Nb) with low hardness dispersed at the interface of alloying layer and substrate. The micro-hardness of chromising layer decreases gradually from HV0.1 1 125 to about HV0.1 400. Pin-on-disk wear test indicates that friction coefficient at room temperature decreases from 0.24 to 0.15 and wear rate is only about 30% of that of matrix at room temperature, while wear rate at elevated temperature deduces by 20% after chromising.
Key words: Ti2AlNb-based alloy; double glow plasma surface alloying; friction; wear
