Two-stage dynamic recrystallization and texture evolution in Al-7Mg alloy during hot torsion  

作　　者：Kwang Tae Son Chang Hee Cho Myoung Gyun Kim Ji Woon Lee 

机构地区：[1]School of Mechanical,Industrial,and Manufacturing Engineering,Oregon State University,Corvallis OR 97331,USA [2]Department of Materials Science Engineering,Northwestern University,Evanston IL 60208,USA [3]Research Institute of Industrial Science and Technology(RIST),Pohang 37673,Rep.of Korea [4]Division of Advanced Materials Engineering,Kongju National University,Cheonan 31080,Rep.of Korea [5]Center for Advanced Materials and Parts of Powders,Kongju National University,Cheonan 31080,Rep.of Korea

出　　处：《International Journal of Minerals,Metallurgy and Materials》2024年第8期1900-1911,共12页矿物冶金与材料学报（英文版）

基　　金：partly supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2020R1C1C1005726);Technology development Program (No. RS-2023-00220823) funded by the Ministry of SMEs and Startups (MSS, Korea);the Electronics Technology Development Project (No. 20026289) funded By the Ministry of Trade, Industry & Energy (MOTIE, Korea);partly supported by the research grant of the Kongju National University in 2022

摘　　要：Hot torsion tests were performed on the Al-7Mg alloy at the temperature ranging from 300 to 500℃ and strain rates between 0.05 and 5 s^(-1) to explore the progressive dynamic recrystallization(DRX)and texture behaviors.The DRX behavior of the alloy manifested two distinct stages:Stage 1 at strain of≤2 and Stage 2 at strains of≥2.In Stage 1,there was a slight increase in the DRXed grain fraction(X_(DRX))with predominance of discontinuous DRX(DDRX),followed by a modest change in X_(DRX) until the transition to Stage 2.Stage 2 was marked by an accelerated rate of DRX,culminating in a substantial final X_(DRX) of~0.9.Electron backscattered diffraction(EBSD)analysis on a sample in Stage 2 revealed that continuous DRX(CDRX)predominantly occurred within the(121)[001]grains,whereas the(111)[110]grains underwent a geometric DRX(GDRX)evolution without a noticeable sub-grain structure.Furthermore,a modified Avrami’s DRX kinetics model was utilized to predict the microstructural refinement in the Al-7Mg alloy during the DRX evolution.Although this kinetics model did not accurately capture the DDRX behavior in Stage 1,it effectively simulated the DRX rate in Stage 2.The texture index was employed to assess the evolution of the texture isotropy during hot-torsion test,demonstrating significant improvement(>75%)in texture randomness before the commencement of Stage 2.This initial texture evolution is attributed to the rotation of parent grains and the substructure evolution,rather than to an increase in X_(DRX).

关 键 词：Al-7Mg alloys hot deformation hot torsion tests dynamic recrystazlliation microstructure texture 

分 类 号：TG146.21[一般工业技术—材料科学与工程]