Twinning and detwinning are the important deformation modes in magnesium alloys during cyclic loading at room temperature. To analyze these two deformation mechanism, cyclic compression–tension experiments were perfo...Twinning and detwinning are the important deformation modes in magnesium alloys during cyclic loading at room temperature. To analyze these two deformation mechanism, cyclic compression–tension experiments were performed on Mg–3Al–1Zn rolled sheet along the rolling direction. In these tests, the microstructure evolutions of a series of grains during deformation were traced by using quasi in situ electron backscatter diffraction(EBSD). Important quantities like the Schmid factors of twinning system, the fraction of twinning during compression, and the fraction of twinning after reverse loading were calculated on the basis of measured quantities. The influence of Schmid factor of twinning variants on detwinning upon reverse loading was analyzed. Detwinning would prefer to proceed during reverse loading if the Schmid factor of twinning in the twinning area before reverse loading is sufficiently large.展开更多
<正>Dimensions of one kind of stainless steel plate before finish rolling were obtained through analysis of the rough rolling processes by finite element method and updated geometrical method.The FE models of fi...<正>Dimensions of one kind of stainless steel plate before finish rolling were obtained through analysis of the rough rolling processes by finite element method and updated geometrical method.The FE models of finish rolling process with a front edge roll were built,and influences of the edge rolling reduction on the stress change in the plate edge during finish rolling were analyzed.The results show that when the edge rolling reduction is increased from 0 mm to 2 mm,the compressive stress in plate corner clearly increases in edge roiling process,and the zone of tensile stress during whole rolling decreases;when the edge rolling reduction is increased from 2 mm to 5 mm, the compressive stress in the plate corner seldom changes,and the compressive stress decreases after the horizontal rolling.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.50775211 and51174189)
文摘Twinning and detwinning are the important deformation modes in magnesium alloys during cyclic loading at room temperature. To analyze these two deformation mechanism, cyclic compression–tension experiments were performed on Mg–3Al–1Zn rolled sheet along the rolling direction. In these tests, the microstructure evolutions of a series of grains during deformation were traced by using quasi in situ electron backscatter diffraction(EBSD). Important quantities like the Schmid factors of twinning system, the fraction of twinning during compression, and the fraction of twinning after reverse loading were calculated on the basis of measured quantities. The influence of Schmid factor of twinning variants on detwinning upon reverse loading was analyzed. Detwinning would prefer to proceed during reverse loading if the Schmid factor of twinning in the twinning area before reverse loading is sufficiently large.
基金Item Sponsored by State Basic Research Key Projects (973) of China (2006CB605208-1) National Natural Science Foundation of China (50534020, 50634030)
文摘<正>Dimensions of one kind of stainless steel plate before finish rolling were obtained through analysis of the rough rolling processes by finite element method and updated geometrical method.The FE models of finish rolling process with a front edge roll were built,and influences of the edge rolling reduction on the stress change in the plate edge during finish rolling were analyzed.The results show that when the edge rolling reduction is increased from 0 mm to 2 mm,the compressive stress in plate corner clearly increases in edge roiling process,and the zone of tensile stress during whole rolling decreases;when the edge rolling reduction is increased from 2 mm to 5 mm, the compressive stress in the plate corner seldom changes,and the compressive stress decreases after the horizontal rolling.