Deciphering the dynamic precipitation and annihilation of GBαdeviating from the conventional variant selection rule in Ti-652 during hot deformation  

作　　者：Yanan Sun Yuhang Gao Shun Xu Lin Yang Qunbo Fan 

机构地区：[1]School of Materials Science and Engineering,Beijing Institute of Technology,Beijing,100081,China

出　　处：《Progress in Natural Science:Materials International》2024年第6期1295-1303,共9页自然科学进展·国际材料(英文版)

基　　金：financially supported by the National Natural Science Foundation of China (grant number 52101005 and 52374380)

摘　　要：Differing from the statically precipitated grain boundaryα(GBα)that holds Burgers Orientation Relationship(BOR)with adjacentβgrains,in this work,it was found that over 97.77%of the dynamically precipitated GBαs do not hold BOR with either side of the adjacentβgrains in hot-forged Ti-652 titanium alloy.The evolution of GBαorientation was decoupled as dynamic precipitation and annihilation,which was quantitatively distinguished by defining three misorientation angles:the deviation form BOR(ω),the misorientation between adjacentβgrains(θ)and the misorientation between non-BOR GBαs(θ').During the entire hot forging,an adequate dynamic precipitation produces piecewise continuous and slender GBαs withω<10°typically,manifesting asθ<25°butθ'>45°.Oppositely,a sufficient annihilation leads to the dynamic globularization of GBαs and increase ofωwithθ≥25°but mainlyθ'≤45°.Dynamic precipitation was driven by the intrinsic BOR preference of GBαs,while annihilation attributed to grain growth and rotation caused by accumulated plastic deformation.Deciphering the dynamic precipitation and annihilation of GBαprovides a quantitative criterion to tailor microstructures and mechanical properties in the future.

关 键 词：Ti-652 alloy Grain boundaryα Dynamic precipitation ANNIHILATION 

分 类 号：TG146.23[一般工业技术—材料科学与工程]