不同频率溅射沉积的新型耐磨二硼化钒涂层的结构及性能

Synthesis and Mechanical Properties of VB_2 Coatings by Pulsed Magnetron Sputtering

采用不同的电源频率沉积新型硬质耐磨VB2涂层。用X射线衍射(XRD)、扫描电镜(SEM)、原子力显微镜(AFM)表征VB2涂层的结构;采用纳米压痕仪、划痕仪、摩擦试验机测试VB2涂层的力学性能和摩擦学性能。XRD结果显示,随着频率增加,VB2涂层衍射峰向小角度偏移,并成(001)面择优取向。频率的增加使得VB2涂层的结构从柱状结构变为类似非晶的致密结构且表面颗粒和粗糙度变小。同时比较不同电源频率下制备的VB2涂层在力学性能及摩擦性能上的差异。本实验制备的VB2涂层硬度达到了43 GPa。VB2涂层的磨损率达到了7.8×10-16m3/N m(M2钢的300多倍)。磨损后形貌显示,其磨道非常光滑,并出现只产生于轻微磨损的卷轴状磨屑。

The VB_2 coatings were synthesized by pulsed magnetron co-sputtering on the substrates of Si（100）, glass and M2 tool steel, pre-deposited with Ti transition layers. The impact of the frequency of power-supply on the microstruc- tures and mechanical properties of the VB_2 coatings was investigated. The VB_2 coatings were characterized with X-ray diffraction, scanning electron microscopy, atomic force microscopy and conventional mechanical probes. The results show that depending on the frequency, the VB_2 coatings possess improved surface mechanical properties, such as higher hard- ness,better wear-resistance and lower friction coefficient. As the frequency increased, the surfaces with big columnar- structured grains turned into amorphous-like surfaces with smaller grains and reduced roughness. Grown at 250 kHz, the 〈 100 〉 preferentially oriented,smooth and compact VB_2 coatings had a surface hardness of 43 GPa,and a wear-rate of 7.8 × 10^-16 m^3/N m,300 times lower than that of M2 tool steel.