2Xinjiang Environmental and Functional Materials Engineering Research Center, School of Materials Science and Engineering, Xinjiang University, Urumqi, Xinjiang 830046, China1School of Chemistry and Pharmaceutical Engineering, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian 271016, China
刊名
Journal of Alloys and Compounds
年份
2025
卷号
Vol.1043
页码
184256
ISSN
0925-8388
摘要
Although the Portevin-Le Chatelier effect, a well-documented plastic instability in aluminum alloys, has been extensively studied, the mechanism underlying the newly discovered linear recovery stress collapse phenomenon remains inadequately elucidated. This gap in understanding limits the overall comprehension of deformation instabilities. By integrating various techniques, including in situ electron backscatter diffraction tensile testing, quasi in situ transmission electron microscope, molec...更多
Although the Portevin-Le Chatelier effect, a well-documented plastic instability in aluminum alloys, has been extensively studied, the mechanism underlying the newly discovered linear recovery stress collapse phenomenon remains inadequately elucidated. This gap in understanding limits the overall comprehension of deformation instabilities. By integrating various techniques, including in situ electron backscatter diffraction tensile testing, quasi in situ transmission electron microscope, molecular dynamics simulations, and damage tracking scanning electron microscope, we have elucidated the multiscale origin mechanisms of three distinct types of LRSC in Al-Zn-Mg alloys. Specifically, Type I LRSC is attributed to grain refinement induced by dynamic discontinuous recrystallization; Type II LRSC results from the combined effects of anomalous phase transformation of the η phase and an anomalous dislocation strengthening mechanism under local triaxial compression; Type III LRSC is induced by damage initiated by adiabatic shear bands in recrystallized soft zones. This study not only establishes LRSC as a novel paradigm of instability that extends beyond the PLC effect but also provides a multiscale framework for designing high-ductility aluminum alloys through the control of recrystallization, phase stability engineering, and heterogeneous structure optimization.收起
