掺硅非晶碳薄膜对TC4摩擦磨损性能的影响

Effect of silicon-doped amorphous carbon films on the tribologicalproperty of TC4

利用C_(2)H_(2)和Si靶,通过等离子体增强化学气相沉积(plasma enhanced chemical vapor deposition, PECVD)和磁控溅射法,在Ti-6Al-4V(TC4)合金表面沉积类金刚石(diamond-likecarbon,DLC)膜层和不同Si含量的Si-DLC膜层。利用拉曼光谱和X射线光电子能谱分析膜层中的键合含量和结构无序性;采用纳米压痕和纳米划痕法测试TC4合金及其膜层试样的力学性能;使用HT-1000高温摩擦磨损测试仪和光学轮廓仪测试TC4合金及其膜层试样的摩擦磨损性能。结果表明:无论是否含Si元素,DLC膜层都能够有效提高TC4基体表面硬度,其中沉积纯DLC膜层后TC4基体的硬度相比无涂层提升了2.4倍,提升率最大;纯DLC和Si的摩尔分数分别为1.79%和3.06%的2种Si-DLC膜层,都可使TC4基体的表面摩擦因数从无涂层的0.64降低至0.1左右,磨损率从无涂层的476.5×10^(-7)mm^(3)/(N·m)降低至0.5×10^(-7)mm^(3)/(N·m)左右,表明这3种膜层都有助于提升TC4基体表面的耐磨性能。

Diamond-like layers and Si-DLC layers with different Si contents on the surface of Ti-6Al-4V(TC4) alloys were fabricated by plasma enhanced chemical vapor deposition(PECVD) and magnetron sputtering using C_(2)H_(2)and Si targets. Raman spectroscopy and X-ray photoelectron spectroscopy(XPS) measurement were used to analyze the bonding content and structural disorder of different films. The mechanical properties of the TC4 alloy and the films deposited were measured by the method of nanoindentation and nano-scratch. The HT-1000 high-temperature friction and wear tester and optical profiler were used to measure the frictional wear properties.The results show that regardless of whether there is Si element in the DLC layer, the surface hardness of TC4substrate can be effectively improved. The hardness of the pure DLC film layer is 2.4 times higher than that of the uncoated TC4, and the improvement rate is the largest among the four films. Pure DLC and two kinds of Si-DLC films with mole fractions of Si of 1.79% and 3.06% respectively, all can reduce the surface friction coefficient of TC4 substrate from 0.64 without coating to about 0.1 and the wear rate is also reduced from 476.5×10^(-7)mm^(3)/(N·m)to about 0.5×10^(-7)mm^(3)/(N·m), indicating that three kinds of coatings are helpful to improve the wear resistance of the TC4 substrate surface.