High-temperature and short-time(HTST)solution heat treatment combined with non-isothermal aging(NIA)was employed to regulate the microstructure and properties of Al−4.5Mg−2.0Zn−0.3Ag alloy.Results indicate that HTST s...High-temperature and short-time(HTST)solution heat treatment combined with non-isothermal aging(NIA)was employed to regulate the microstructure and properties of Al−4.5Mg−2.0Zn−0.3Ag alloy.Results indicate that HTST solution heat treatment can not only retain partial deformation dislocations,but inhibit the recrystallization behavior and increase the proportion of low-angle grain boundaries(LAGBs).In the subsequent NIA process,HTST solution heat treatment combined with NIA is instrumental in restraining the degradation of dislocations and promoting precipitation of nano-scale T'-Mg_(32)(Al,Zn,Ag)49 phase,which improves the strength of the alloy greatly.In addition,a higher fraction of LAGBs and the discontinuous distribution of grain boundary precipitates caused by this novel technology meliorate the corrosion resistance of Al−4.5Mg−2.0Zn−0.3Ag alloy.展开更多
The microstructural evolution of AA6061 and Mn-bearing Al-Mg-Si-Cu alloys was studied by compression tests that were carried out between 300 and 500 °C with a wide range of strain rates. Compared to the AA6061 al...The microstructural evolution of AA6061 and Mn-bearing Al-Mg-Si-Cu alloys was studied by compression tests that were carried out between 300 and 500 °C with a wide range of strain rates. Compared to the AA6061 alloy, the large amount of α-Al(MnFeCr)Si dispersoids in the Mn-bearing alloy yielded a significant increase in the flow stress under all deformation conditions. The effects of the deformation parameters on the evolution of the microstructure were studied using electronic backscatter diffraction measurements. The predominant softening mechanism of both alloys was dynamic recovery. The presence of α dispersoids in Mn-bearing alloys effectively refined the size of substructures with misorientation angles in the range of 2°-5°, which retarded the dynamic recovery. To predict the subgrain size under various deformation conditions, the threshold stresses that were caused by α dispersoids were calculated by the modified Orowan equation and incorporated into a conventional constitutive equation. The subgrain size that was predicted by the modified constitutive equation showed satisfactory agreement with the experimental measurements.展开更多
基金National Natural Science Foundation of China(Nos.52204400,52204401)Natural Science Foundation of Hebei Province,China(No.E2022203033)。
文摘High-temperature and short-time(HTST)solution heat treatment combined with non-isothermal aging(NIA)was employed to regulate the microstructure and properties of Al−4.5Mg−2.0Zn−0.3Ag alloy.Results indicate that HTST solution heat treatment can not only retain partial deformation dislocations,but inhibit the recrystallization behavior and increase the proportion of low-angle grain boundaries(LAGBs).In the subsequent NIA process,HTST solution heat treatment combined with NIA is instrumental in restraining the degradation of dislocations and promoting precipitation of nano-scale T'-Mg_(32)(Al,Zn,Ag)49 phase,which improves the strength of the alloy greatly.In addition,a higher fraction of LAGBs and the discontinuous distribution of grain boundary precipitates caused by this novel technology meliorate the corrosion resistance of Al−4.5Mg−2.0Zn−0.3Ag alloy.
基金financially supported by National Natural Science Foundation of China(U1864209)Shanxi Province Key Research and Development Plan Project(201903D211002)Shanxi Agricultural University Doctorat(SXBYKY2021021,2020BQ80)。
基金the financial supports from the National Natural Science Foundation of China (No. U1864209)Jincheng Science and Technology Plan Project of Shanxi Province, China (No. 201702014)。
文摘The microstructural evolution of AA6061 and Mn-bearing Al-Mg-Si-Cu alloys was studied by compression tests that were carried out between 300 and 500 °C with a wide range of strain rates. Compared to the AA6061 alloy, the large amount of α-Al(MnFeCr)Si dispersoids in the Mn-bearing alloy yielded a significant increase in the flow stress under all deformation conditions. The effects of the deformation parameters on the evolution of the microstructure were studied using electronic backscatter diffraction measurements. The predominant softening mechanism of both alloys was dynamic recovery. The presence of α dispersoids in Mn-bearing alloys effectively refined the size of substructures with misorientation angles in the range of 2°-5°, which retarded the dynamic recovery. To predict the subgrain size under various deformation conditions, the threshold stresses that were caused by α dispersoids were calculated by the modified Orowan equation and incorporated into a conventional constitutive equation. The subgrain size that was predicted by the modified constitutive equation showed satisfactory agreement with the experimental measurements.
