Introducingωand O'nanodomains in Ti-6Al-4V:The mechanism of acceleratingα→βtransformation kinetics via electropulsing  

作　　者：Yachong Zhou Xiaofeng Xu Yang Zhao Xudong Yan Lai Wei Zhicheng Wu Chao Wu 

机构地区：[1]Key Laboratory of Automobile Materials,Ministry of Education,Department of Materials Science and Engineering,Jilin University,Changchun 130000,China [2]Weihai Institute for Bionics-Jilin University,Weihai 264200,China [3]Key Laboratory of Bionic Engineering,Ministry of Education,Jilin University,Changchun 130000,China

出　　处：《Journal of Materials Science & Technology》2023年第31期109-117,共9页材料科学技术（英文版）

基　　金：Financial support from the National Key Research and Development Program of China(Nos.2020YFB008300,2020YFB008303,and 2020YFB008304);Provincial Natural Science Foundation of Shandong(No.ZR202102220408);National Natural Science Foundation of China(No.51701080);Talent Development Excellent Young Talents Fund Project China(No.20190103053JH).

摘　　要：Conventional kinetics theory for diffusion-controlled phase transformation shows that the reverse transition should lag behind the temperature rise through rapid heating,i.e.,overheating is required.In this work,we found that theβ-transus temperature decreased by∼50℃ during studying theα→βtransformation in Ti-6Al-4V alloy via electropulsing treatment(EPT).The calculation suggests that the acceleration of transformation kinetics cannot be fully explained by Joule heat and athermal effects of the electromigration effect and electron wind theory.The microstructural evolution during EPT was systematically investigated utilizing scanning electron microscope(SEM),electron backscattered diffraction(EBSD),X-ray diffraction(XRD),transmission Kikuchi diffraction(TKD),and transmission electron micro-scope(TEM).Microscopic analysis shows that the nano-sizedωand O'phases formed in theβphase,which causes large numbers of lattice distortion regions.The defects are conducive to accelerating the bulk diffusion of alloying elements inβ.Moreover,the nanodomains limited the growth of martensite,therefore nanocrystalline martensite formed after quenching.These findings develop the understanding of the destructive effect of current on metallic crystal,which will help to guide microstructural regulation in titanium and other alloys.

关 键 词：Titanium alloy Phase transformation kinetics ELECTROPULSING Nanodomain DIFFUSION 

分 类 号：TG146.23[一般工业技术—材料科学与工程]