等通道弯角挤压纯钛组织及电化学腐蚀性能研究  

Microstructures and electrochemical corrosion properties of commercially pure titanium processed by multi-pass equal channel angular extrusion

作　　者：江鸿[1] 范志国 雷君相[1] 谢超英[3] 

机构地区：[1]上海理工大学材料科学与工程学院,上海200093 [2]奥的斯电梯管理(上海)有限公司,上海201203 [3]上海交通大学材料科学与工程学院,上海200240

出　　处：《功能材料》2016年第B12期32-37,共6页Journal of Functional Materials

基　　金：上海市自然科学基金资助项目(A13ZR1427900);上海高校青年教师培养资助计划资助项目(slg14050)

摘　　要：在400℃采用BC路径等通道弯角挤压对工业纯钛进行了8道次处理,用透射电镜分析了微观组织,并以林格式人工模拟体液为腐蚀介质,采用电化学阻抗谱对耐蚀性进行了研究。结果表明,8道次后纯钛主要由细小等轴晶粒所构成,平均晶粒尺寸<500 nm。不同道次处理后,纯钛腐蚀性能排序为退火粗晶态<2道次<1道次<4道次<8道次。8道次后耐蚀性能最优,2道次却弱于1道次。2道次后晶粒细化,但大变形引起织构组分改变使得平行于样品表面的晶面由上一道次(011-0)晶面演变成高指数晶面(112-0),导致耐蚀性能下降,表明纯钛耐腐蚀行为同时受到晶粒尺寸和织构的影响。Commercially pure Ti was prepared by multi-pass ECAE at 400 ℃ via route Bc. The microstructures evolution were characterized by transmission election microscopy(TEM).The electrochemical corrosion behaviors in Ringer's solution were investigated by electrochemical impedance spectroscopy(EIS) measurement. After eight-passes ECAE treatment,the microstructure becomes more homogeneous and the fraction of fine equiaxed grains increases,smaller than 0.5μm.The corrosion resistance of CP-Ti sample with different pass ECAE treatment increases in the order of zero-pass,two-passes,one-pass,four-passed and eight-passes. The eight-passes ECAEed CP-Ti have the best corrosion resistance. The corrosion resistance of two-passes sample is not inferior to one-pass although the microstructure is refined. The crystallographic plane parallel to the surface of ECAEed samples is changed from(011-0) plane in one-pass to(112-0)high index plane in two- passes and results the reduce of corrosion resistant performance. It indicates that the electrochemical corrosion behaviour of CP- Ti is effected simultaneously by grain size and texture during multi- pass ECAE process.

关 键 词：纯钛 微观组织 电化学阻抗谱 EACE 织构 

分 类 号：TG146.2[一般工业技术—材料科学与工程]