氧含量对纯钛动态变形行为的影响  

Effect of Oxygen Content on Dynamic Deformation Behavior of Pure Titanium

作　　者：王博雅 骆雨萌 刘睿 宋晓云 于洋 叶文君 惠松骁 Wang Boya;Luo Yumeng;Liu Rui;Song Xiaoyun;Yu Yang;Ye Wenjun;Hui Songxiao(State Key Laboratory of Nonferrous Metals and Processes,China GRINM Group Co.,Ltd,Beijing 100088,China;GRIMAT Engineering Institute Co.,Ltd,Beijing 101407,China;General Research Institute for Nonferrous Metals,Beijing 100088,China;GRINM(Guangdong)Institute for Advanced Materials and Technology,Foshan 528051,China)

机构地区：[1]中国有研科技集团有限公司有色金属材料制备加工国家重点实验室,北京100088 [2]有研工程技术研究院有限公司,北京101407 [3]北京有色金属研究总院,北京100088 [4]有研(广东)新材料技术研究院,广东佛山528051

出　　处：《稀有金属材料与工程》2024年第6期1517-1522,共6页Rare Metal Materials and Engineering

摘　　要：通过准原位EBSD和SEM观察研究了纯钛、Ti-0.2%O和Ti-0.4%O(质量分数)多晶体在高应变速率下的变形行为。结果表明:在5%应变的动态压缩变形下,纯钛中的孪生行为非常活跃,多数晶粒内的孪生系被激活,且半数晶粒中出现多种孪生变体;而滑移迹线分析表明,仅有50%的晶粒内开动了滑移系。随着氧含量的增加,孪生晶粒比例及孪晶面积占比均呈下降趋势,同时发生多滑移与交滑移。XRD分析表明,溶质氧原子导致晶格畸变,提高了α-Ti的c/a,有利于位错滑移。活跃的位错滑移行为抑制了孪晶的形成,并且氧原子钉扎位错也会阻碍孪晶界的扩展,导致孪生行为不再活跃。此外,氧含量每增加0.2%(质量分数),纯钛的动态屈服强度就能增加约390 MPa。这种固溶强化现象主要源于晶格畸变,也受到被钉扎位错及多滑移和交滑移产生的割阶影响。The deformation behavior of pure Ti,Ti-0.2wt%O,and Ti-0.4wt%O polycrystals under high strain rate was investigated by quasi-in-situ EBSD and SEM observation.Results show that under dynamic compressive deformation of 5%strain,the twinning behavior in pure Ti is very active,the twins in most grains are activated,and multiple twin variants appear in half of the grains.However,the slip trace analysis shows that the slip systems are activated in only 50%grains.With the increase in oxygen content,the proportion of twins and the twin area ratio are decreased,and multiple slips and cross slip are activated in the meantime.XRD analysis reveals that the solute oxygen atoms cause the lattice distortion and increase the c/a ratio inα-Ti,which is beneficial to the dislocation slip.The active dislocation slip inhibits the twin nucleation,and the oxygen atoms can pin dislocations to hinder the expansion of twinning boundaries.Thus,the twinning behavior is no longer active.In addition,the dynamic yield strength of pure Ti increases by about 390 MPa for every 0.2wt%increase in oxygen content.This solution hardening phenomenon mainly originates from the lattice distortion,and it is also influenced by the pinned dislocations and the jogs resulting from multiple slips and cross slip.

关 键 词：纯钛 氧含量 变形机制 准原位 高应变速率 

分 类 号：TG146.23[一般工业技术—材料科学与工程]