硫酸溶液中TC4合金电化学腐蚀与摩擦行为研究

Electrochemical corrosion and friction behavior of TC4 alloy in H2SO4 solution

针对钛合金冷拉拔出现的表面加工硬化、加工效率低;以及产品表面平整性差的现存问题,探索研究钛合金在腐蚀介质下的电化学腐蚀对其表面摩擦学行为的影响及其机制,以期为未来钛合金电化学拉拔工艺应用提供理论基础。采用球-盘式往复摩擦试验机、电化学工作站研究TC4钛合金在硫酸溶液中的电化学腐蚀摩擦行为,分析不同外加电位、滑动速度与摩擦系数、磨损形貌的关系。结果表明:滑动摩擦产生的接触区局部塑性变形促进了磨痕处阳极溶解,引起开路电位负移与腐蚀电流增大。当外电位从-0.3 V增大到1.0 V,摩擦系数先减小后增大。在外加阳极电位促进腐蚀作用下,试样表层的腐蚀产物能够对其表面形貌与磨损机制产生影响,从而有效改善TC4表面的摩擦学性能。

Aiming at the existing problems of surface working hardening,low processing efficiency and poor product surface evenness in cold drawing of titanium alloy,the influence of electrochemical corrosion of titanium alloy in corrosive medium on its surface tribological behavior and its mechanism were explored,so as to provide theoretical basis for the application of electrochemical drawing technology of titanium alloy in the future.The electrochemical corrosion friction behavior of TC4 titanium alloy in H2SO4 solution was studied by ball-disc reciprocating friction testing machine and electrochemical method,and the relationship between different applied potential,sliding velocity,friction coefficient and wear morphology was analyzed.The results show that the local plastic deformation of the contact area caused by sliding friction promotes the dissolution of the anode at the wear mark and causes the negative open circuit potential and corrosion current to increase greatly.When the external electric potential increases from-0.3v to 1.0v,the friction coefficient decreases first and then increases.Under the simultaneous action of applied potential and chemical corrosion,the corrosion products on the surface of the sample could influence its surface morphology and wear mechanism,thus effectively improving the tribological properties on the surface of TC4.