Influence of Pre-deformation on Phase Transformations and Microstructures in Near β Ti Alloy During Aging  

预变形对近β钛合金时效阶段的相变及微观组织影响

作　　者：Song Bo Xi Honglei Fu Yu Wang Junshuai Xiao Wenlong Ren Yanbiaot Ma Chaoli 宋博;郗洪雷;付雨;王俊帅;肖文龙;任衍彪;马朝利(聊城大学材料科学与工程学院,山东聊城252059;北京航空航天大学材料科学与工程学院,北京100191;天目山实验室,浙江杭州310023;枣庄学院化学工程与材料科学学院,山东枣庄277160)

机构地区：[1]School of Materials Science and Engineering,Liaocheng University,Liaocheng 252059,China [2]School of Materials Science and Engineering,Beihang University,Beijing 100191,China [3]Tianmushan Laboratory,Hangzhou 310023,China [4]College of Chemistry,Chemical Engineering and Materials Science,Zaozhuang University,Zaozhuang 277160,China

出　　处：《稀有金属材料与工程》2024年第11期3001-3009,共9页Rare Metal Materials and Engineering

基　　金：Natural Science Foundation of Shandong Province(ZR2022QE115);Liaocheng City Key Research Plan(2022YDSF85);Liaocheng University Doctoral Initiation Fund(318052132);Liaocheng University Students Innovation Plan(CXCY2023029);National Natrual Science Foundation of China(51671012,51671007,52174346);International Science and Technology Cooperation Program of China(2015DFA51430);Aeronautical Science Foundation of China(2015ZF51069)。

摘　　要：The influence of pre-deformation on phase transformations,microstructures and hardening response in nearβTi alloy Ti5Al-3Mo-3V-2Cr-2Zr-1Nb-1Fe(wt%)during aging treatment was studied.The results show that obviousαphase refinement and stronger age hardening effect can be achieved when the alloy is slightly deformed before aging treatment.Because the formation of intermediate phases(O′,ωand O′′)suppresses long-range stress induced martensitic transformation and mechanical twinning,the alloy is mainly deformed via dislocation slipping during loading.Large numbers of crystal defects are generated during predeformation.With increasing the predeformation,the number density of dislocations increases gradually.These crystal defects generated by pre-deformation may partly annihilate upon early aging,but the precipitation ofαcan also be promoted,resulting in refinedαprecipitates.In the sample with 5%pre-strain,the average thickness ofαprecipitates decreases by 57%after aging at 600℃ compared with the sample without pre-strain,and the number density increases from 7.0±1 laths/μm^(2)to 22.0±3 laths/μm^(2).Some platelet-shapedαphases form when the samples experience comparably large pre-strains such as 12%and 20%.It proves that the refinedαprecipitates and better hardening effect can be achieved by pre-deformation plus aging treatment for titanium alloy.研究了预变形对近β钛合金Ti-5Al-3Mo-3V-2Cr-2Zr-1Nb-1Fe(质量分数,%)在时效处理中相变、微观组织及强化响应的影响。结果表明,合金经预变形后再进行时效处理可以获得明显细化的α相与更好的时效强化效果。由于中间相O′、ω和O′′的形成抑制了长程应力诱导马氏体相变机制和机械孪晶,合金变形主要是通过位错滑移机制。预变形过程中会产生大量晶格缺陷,随着预变形量的增大,位错数量密度逐渐上升。这些由预变形产生的晶格缺陷会在时效初期部分湮灭,但是仍然能够促进α相析出,实现α相细化。与未预变形的样品相比,预变形量为5%的样品在600℃时效后α相的平均宽度会下降57%,而且数量密度由7.0±1 laths/μm^(2)上升至22.0±3 laths/μm^(2)。当预变形量较大时,如12%和20%,会形成板条状的α相,这说明钛合金经预变形后再时效处理可以获得细化的α相与更好的强化效果。

关 键 词：titanium alloy pre-deformation plus aging treatment intermediate phases αprecipitate 

分 类 号：TG146.23[一般工业技术—材料科学与工程]