钛合金表面W-Mo共渗层耐磨性研究

Research on Wear Resistance of W-Mo Penetrating Layer on Titanium Alloy Surface

利用针状等电位空心阴极辉光放电技术,在钛合金（Ti6Al4V）表面进行W-Mo共渗。利用扫描电镜（SEM）观察了W-Mo共渗改性层的表面形貌和截面形貌;采用能谱仪（EDS）检测了改性层元素含量分布;采用X射线衍射仪（XRD）分析了改性层的相结构;利用球-盘摩擦磨损试验仪测试了共渗层在室温和高温干摩擦条件下的耐磨性能。结果表明：在750℃条件下,共渗处理3h后,在钛合金表面形成了厚度约为23.1μm的W-Mo改性层。改性层主要由AlMoTi2和TixW（1-x）相组成。相比于Ti6Al4V基体的摩擦系数,在室温和500℃干摩擦条件下改性层的平均摩擦系数仅为0.21和0.38。摩擦系数显著降低,说明耐磨性能显著提高。

W-Mo penetrating on the surface of titanium alloy （Ti6Al4V） was carried out by needle-shape equipotential hollow cathode glow discharge technique. The surface morphology and cross sectional morphology of W-Mo penetrating modified layer were analyzed by scanning electron microscopy （SEM）, The element distribution of W-Mo penetrating modified layer was analyzed by energy dispersive spectroscope （EDS）. The phase structuxe of the modified layer was analyzed by X-ray diffraction （XRD）. The wear-resisting properties of the modified layer at room temperature and high temperature under dry sliding were tested on a ball-on-disc frictional wear tester. The results show that the modified layer with the thickness of 23.1 p,m can be obtained on the surface of Ti6Al4V alloy when treated at 750 ℃ penetrating for 3 h. The modified layer mainly consists of AlMoTi2 and TixW1-x phases. Compared with friction coefficient of Ti6Al4V substrate, the average friction coefficients of the modified layer are only 0.21 and 0.38 under dry sliding at room temperature and 500 ℃, respectively. The friction coefficient significantly decreases, which indicates that the wear resistance improves.