The growth of vitamin C single crystals was studied by direct observation In flowing solution, the linear growth rates of three orientations (, , ) were measured for vitamin C water system The experiments were designe...The growth of vitamin C single crystals was studied by direct observation In flowing solution, the linear growth rates of three orientations (, , ) were measured for vitamin C water system The experiments were designed as orthogonal test to investigate the effect of various factors Comparing with temperature and velocity, supersaturation is the most important factor And the relations between growth and supersaturation were different with crystal directions, which obviously show anisotropy The order of magnitude of G , G , G and their dependency on supersaturation ( g , g , g ) were in good agreement with analysis of maximum difference The effect of solution diffusion could be neglected and crystal growth was controlled by surface reaction According to the growth models, the growth mechanism was展开更多
The grain growth morphology,kinetics and texture change after uniaxial compression at 430 ℃ of an extruded AZ31 alloy were studied.The samples were loaded following two routes insuring two initial textures of the sam...The grain growth morphology,kinetics and texture change after uniaxial compression at 430 ℃ of an extruded AZ31 alloy were studied.The samples were loaded following two routes insuring two initial textures of the samples with compression direction parallel and normal to the extrusion direction.For both initial textures,a stable grain size is attained upon isothermal annealing and the grain growth kinetics can be described by:dn= dRn+kt with an n value of around 15.The annealing texture with grown grains is a retained hot deformation texture without emerging or strengthening other components.Abnormal grain growth is not observed for annealing time up to 10 000 h at 450℃.展开更多
文摘The growth of vitamin C single crystals was studied by direct observation In flowing solution, the linear growth rates of three orientations (, , ) were measured for vitamin C water system The experiments were designed as orthogonal test to investigate the effect of various factors Comparing with temperature and velocity, supersaturation is the most important factor And the relations between growth and supersaturation were different with crystal directions, which obviously show anisotropy The order of magnitude of G , G , G and their dependency on supersaturation ( g , g , g ) were in good agreement with analysis of maximum difference The effect of solution diffusion could be neglected and crystal growth was controlled by surface reaction According to the growth models, the growth mechanism was
文摘The grain growth morphology,kinetics and texture change after uniaxial compression at 430 ℃ of an extruded AZ31 alloy were studied.The samples were loaded following two routes insuring two initial textures of the samples with compression direction parallel and normal to the extrusion direction.For both initial textures,a stable grain size is attained upon isothermal annealing and the grain growth kinetics can be described by:dn= dRn+kt with an n value of around 15.The annealing texture with grown grains is a retained hot deformation texture without emerging or strengthening other components.Abnormal grain growth is not observed for annealing time up to 10 000 h at 450℃.
