体心立方近β钛合金循环形变中的平面滑移行为  

Planar Slip Behavior of Near-β Titanium Alloy during Cyclic Deformation Process

作　　者：黄俊[1,2] 李慧[1] 王执锐[2] 吴玉程[1,3] 

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009 [2]多伦多大学材料科学与工程系 [3]安徽省有色金属材料与加工工程实验室,合肥230009

出　　处：《机械工程材料》2014年第3期5-9,38,共6页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(51201054);中国博士后基金资助项目(2012M511400);教育部科学研究重大项目(311025);教育部博士点基金新教师类项目(20120111120030)

摘　　要：对单相体心立方近β钛合金在不同加载应力以及循环周次下进行压缩疲劳试验,对循环过程中的范性应变机制进行分析,通过研究滑移模式、显微组织演化等对早期微裂纹萌生的影响以及观察疲劳前后位错组态的演化,分析了循环形变特征与表面滑移模式之间的内在联系。结果表明:单相近β钛合金经纯压缩循环形变后出现出典型的平面滑移特征以及表面应力集中现象,循环形变后的位错湮灭、退孪晶和孪晶界结构简化造成的局部应力改变是导致应力集中滑移带出现以及平面滑移机制的重要因素。Fatigue experiments for bcc near-β Ti alloy were carried out under the conditions of different strains and cycles, and the plastic strain mechanism during cycle was analyzed. Internal relation between cyclic deformation characteristic and surface slid mode was analyzed by studying theeffects of slip mode, microstructure evolution on early micro-cracks initiation and observing dislocation configuration before and after fatigue testing. The results show that typical planar slip characteristic and surface stress concentration appeared in near-β Ti alloy after compressive cyclic deformation. The stress-localized slip bands as well as the planar slip mechanism were induced by the dislocation annihilation, detwinning progress, and the simplified microstructure upon the stress cycling.

关 键 词：近Β钛合金 压缩疲劳试验 循环形变 平面滑移 位错演化 

分 类 号：TG111[金属学及工艺—物理冶金]