TC11钛合金在人造海水中的腐蚀磨损特性研究

Corrosion Wear Characteristic of TC11 Alloy in Artificial Sea Water

采用球-面接触方式,在振幅为5 mm条件下研究了TC11钛合金在人造海水和纯净水中的往复滑动腐蚀磨损行为,采用扫描电子显微镜观察磨屑和磨痕表面形貌,用能谱仪测试微区元素分布,用非接触式表面形貌仪测定磨痕的三维表面形貌及其磨损体积损失,研究了载荷、滑动频率以及介质对TC11钛合金摩擦系数和磨损量的影响,并用动电位扫描法分析TC11在腐蚀磨损前后的电化学行为.结果表明:在2种介质中TC11钛合金的摩擦系数均随着载荷和滑动频率的增加而呈下降趋势,但随载荷变化的趋势更为缓慢;TC11钛合金在海水中形成的润滑膜可以明显降低摩擦系数,但其磨损量比水介质中高,说明腐蚀加速了磨损;磨损后的钝化膜更易被破坏,TC11钛合金在水中的磨损机制为磨粒磨损,而在海水中则为疲劳脱落并伴有磨粒磨损.

The corrosion wear behavior of titanium alloy TCll flat was investigated in artificial sea water and distilled water by using ball-on-flat configuration with 5 mm reciprocating amplitude. The morphology and composition of the wear scars were observed and analyzed by using scanning electron microscopy with energy dispersive spectroscopy. 3D-morphology and wear volume loss were determined by using a non-contact optical profilometer. The influences of the load, frequency and media on the friction coefficient and wear volume of TC11 were analyzed. The po- tentiodynamic anodic polarization was used to study the corrosion behavior of the TC11 before and after the corrosion wear. The friction coefficient of TC11 decreased with increasing frequency or load in both media, but the trends of the friction coefficient were slighter affected by normal load than that affected by frequency. The lubrication surface film formed on the wear scars in the artificial seawater could reduce the friction coefficient. But the wear volume of TC11 in the artificial seawater was always higher than that in the distilled water, which demonstrates that the corrosion of seawater accelerated the wear. The potentiodynamic anodic polarization curves indicated that the passive film was easier to breakdown after wear. The wear mechanism of TC11 in water was only abrasion wear, whereas in sea- water, it became delamination fatigue associated with abrasive wear.