Effect of pre-twinning and heat treatment on formability of AZX311 Mg alloy  

作　　者：Mahesh Panchal Lalit Kaushik Min-Seong Kim Ravi Kottan Renganayagalu Shi-Hoon Choi Jaiveer Singh 

机构地区：[1]Department of Mechanical Engineering,Indian Institute of Technology Jodhpur,Karwar,Jodhpur 342030,Rajasthan,India [2]Department of Metallurgical and Materials Engineering,Indian Institute of Technology Jodhpur,Karwar,Jodhpur 342030,Rajasthan,India [3]Energy Materials Research Center,Korea Institute of Science and Technology(KIST),5 Hwarang-ro,Seongbuk-gu,Seoul 02792,Republic of Korea [4]Department of Advanced Components and Materials Engineering,Sunchon National University,255 Jungang-ro,Suncheon,Jeonnam 57922,Republic of Korea

出　　处：《Journal of Magnesium and Alloys》2024年第3期1154-1169,共16页镁合金学报（英文）

基　　金：supported by the Science and Engineering Research Board(SERB),a statutory body of the Department of Science&Technology(DST),Government of India through the Start-up Research Grant(SRG)scheme(File No.SRG/2020/000341).

摘　　要：In this study,the effects of pre-strain-induced tensile twins(TTWs)and controlled heat treatment on the formability behavior of AZX311 Mg alloy sheets were investigated.A 4%compressive strain was applied to pre-strain the sheets using the in-plane compression(IPC)technique along the rolling direction(RD)to introduce TTWs.The pre-strained(PS)samples were subsequently heat-treated at 250℃,350℃,and 400℃ independently for 1 hr,and are termed as PSA1,PSA2,and PSA3,respectively.Erichsen cupping tests were conducted to assess the formability of the sheet samples under different initial conditions.The results showed that the PS sample heat-treated at 250℃ for 1hr exhibited a decrease in the Erichsen index(IE)compared to the as-rolled sample,whereas PSA2 and PSA3 samples showed an increase in IE values.Microtexture analysis revealed that most of the TTWs generated through pre-twinning were stable at 250℃;however,the twin volume fraction reduced to 41%at 350℃ compared to the PS samples due to enhanced thermal activity at that temperature.Furthermore,PSA2 samples showed severe grain coarsening in some areas of the sample,and the fraction of such grains increased in the PSA3 samples.The stretch formability(IE value)of PSA2 samples showed a 32.3%increase compared to the as-rolled specimens.Additionally,the analysis of the deformed specimen at failure under the Erichsen test indicated that considerable detwinning occurs in the PS and PSA1 samples,whereas dislocation slip activity dominates in the PSA2 and PSA3 samples during stretch forming.Apart from detwinning and dislocation slip,deformation twins were also observed in all samples after the Erichsen test.Thus,this work highlights the importance of texture control and its underlying mechanisms via pre-twinning followed by heat treatment and their impact on the room temperature(RT)stretch formability of AZX311 Mg alloy sheets.

关 键 词：Mg alloys Pre-twinning Texture FORMABILITY EBSD. 

分 类 号：TG156[金属学及工艺—热处理] TG146.22[金属学及工艺—金属学]