轧制变形超细晶纯钛的电化学腐蚀行为

Electrochemical corrosion behaviors of ultrafine-grained commercially pure titanium processed by rolling

工业纯钛经过8道次等通道弯角挤压处理后,在室温或液氮温度下进行轧制。随后以林格式人工模拟体液为腐蚀介质,对两步大变形前后纯钛的电化学腐蚀行为进行了研究。结果表明,8道次ECAE处理后获得的超细晶纯钛,较退火粗晶态具有更好的轧制变形能力。两步大变形制备超细晶纯钛不仅表现出良好的综合力学性能,而且具备优异的耐腐蚀性能。8道次ECAE处理的纯钛在室温冷轧后的耐腐蚀性较液氮温度冷轧后好,主要因为不同温度轧制织构组分改变使得平行于样品表面的晶面变为密排面或低指数晶面,比高指数晶面难溶解,呈现更优的耐腐蚀性能。

The commercially pure （CP） Ti was treated by eight-passes equal channel angular extrusion （ECAE） and then by cold rolling at room temperature or liquid nitrogen temperature. The electrochemical corrosion behaviors of CP-Ti before and after two-step severe plastic deformation （SPD） were investigated in Ringer＇s solution. The results indicate that ultrafine-grained （UFG） CP-Ti after eight-passes ECAE shows better ability of rolling deformation than coarse-grained （CG） CP-Ti. UFG CP-Ti after SPD not only shows good comprehensive mechanical properties but also has excellent corrosion resistance. The corrosion resistance of eight-passes ECAEed CP-Ti after cold rolling at liquid nitrogen temperature is inferior to the sample after eight-passes ECAE and cold roiling at room temperature, for the texture components change with different rolling temperatures and the crystallographic plane parallel to the surface of rolled samples changes to low index plane or close-packed plane, which is difficult to dissolve and has better corrosion resistant performance than high index plane.