TC4钛合金表面微织构干摩擦特性

Surface dry tribological properties of TC4 titanium alloy with micro texture

为改善TC4钛合金表面摩擦学性能,采用皮秒紫外激光技术在TC4钛合金表面加工了3种形状的微织构。使用多功能摩擦磨损试验机研究了织构化TC4钛合金在多接触条件下的摩擦学特性,并采用显微硬度仪、扫描电镜、激光共聚焦显微镜对织构化TC4钛合金的表面硬度、表面粗糙度、磨痕三维轮廓和磨痕形貌等进行分析。结果表明,织构化TC4表面硬度提升约60%,其中三角形凹坑织构表面综合硬度最高;微织构能有效降低TC4表面接触过程的摩擦系数,其中圆形与矩形织构摩擦系数最低,较无织构表面减少约10%;微织构能捕获磨屑,减少磨粒磨损,提高耐磨性能,相同接触条件下,织构化试样磨损量减少了50%;当载荷一定时,速度增加可使织构化TC4表面摩擦系数降低;当摩擦速度一定时,载荷降低可导致织构化TC4表面摩擦系数降低。本研究可为提升钛合金表面摩擦学性能提供研究思路,减少钛合金因摩擦磨损造成的损失与事故。

To improve the surface tribological properties of TC4 titanium alloy,three kinds of micro textures have been processed on the surface of TC4 titanium alloy by picosecond ultraviolet laser technology.The tribological properties of the textured TC4 titanium alloy under multi-contact conditions were investigated by multifunctional friction and wear testing machine.The surface hardness,surface roughness,three-dimensional profile and morphology of wear marks of textured TC4 titanium alloy were analyzed by microhardness tester,scanning electron microscope and laser confocal microscope.The results reveal that the surface hardness of textured TC4 surface increases by about 60%,and the triangular textured surface shows the highest hardness.Micro texture effectively reduces the friction coefficient of the TC4 surface.The circular and rectangular textured surfaces indicate the lowest friction coefficient,about 10%lower than that of non-textured surface.Capable of capturing the wear debris,the micro texture can reduce abrasive wear and improve wear resistance.Under the same contact conditions,the wear volume of textured samples is reduced by about 50%compared with no-textured surface.When the load is constant,the friction coefficient of textured TC4 surface decreases with the increase of velocity.Under the same wear speed,the lower load leads to a decrease of friction coefficient on the textured TC4 surface.This study presents an effective way to improve the tribological properties of titanium alloy,providing an alternative way to reduce the loss and failure caused by the friction and wear on titanium alloy.