A method for recycling AZ91D magnesium alloy scraps directly by hot extrusion was studied.Various microstructural analyses were performed using the techniques of optical microscopy,scanning electron microscopy(SEM)and...A method for recycling AZ91D magnesium alloy scraps directly by hot extrusion was studied.Various microstructural analyses were performed using the techniques of optical microscopy,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).Microstructural observations revealed that all the recycled specimens consisted of fine grains due to the dynamic recrystallization.The main strengthening mechanism of the recycled specimen was grain refinement strengthening and homogeneous distribution of oxide precipitates.The interfaces of individual scraps of extruded materials were not identified when the scraps were extruded with the extrusion ratio of 40-1.Oxidation layers of the scraps were broken into pieces by high compressive and shear forces under the extrusion ratio of 40-1.The ultimate tensile strength and elongation to failure increased with increasing the extrusion ratio.Recycled specimens with the extrusion ratio of 40:1 showed higher ultimate tensile strength of 342.61 MPa and higher elongation to failure of 11.32%,compared with those of the cast specimen.展开更多
Separation of refined soybean oil/n-hexane miscellas was studied using different commercial ultra- and nanofiltration membranes, with cut-oil＇s in the range of 1 to 5 kDa and salt rejection higher than 97% （MgSO4）....Separation of refined soybean oil/n-hexane miscellas was studied using different commercial ultra- and nanofiltration membranes, with cut-oil＇s in the range of 1 to 5 kDa and salt rejection higher than 97% （MgSO4）. Commercial soybean oil and n-hexane miscellas with 1：3 and 1：1 mass ratios were permeated in a dead-end module. The effects of the feed pressure （2-25 bar） on oil and n-hexane fluxes and rejection were investigated. Oil rejection ranged from negative values to 30.8%, soybean oil flux from 28.9 to 617.8 g/m2 hl and n-hexane flux from 8.5 to 1,078.5 g m2 hl. Membrane fouling was observed at all experimental conditions studied. The membrane separation process has proven to be a promising alternative to solvent recovery in soybean oil extraction.展开更多
基金Projects(50674038, 50974048) supported by the National Natural Science Foundation of ChinaProject(200802140004) supported by Doctoral Fund of Ministry of Education of China
文摘A method for recycling AZ91D magnesium alloy scraps directly by hot extrusion was studied.Various microstructural analyses were performed using the techniques of optical microscopy,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).Microstructural observations revealed that all the recycled specimens consisted of fine grains due to the dynamic recrystallization.The main strengthening mechanism of the recycled specimen was grain refinement strengthening and homogeneous distribution of oxide precipitates.The interfaces of individual scraps of extruded materials were not identified when the scraps were extruded with the extrusion ratio of 40-1.Oxidation layers of the scraps were broken into pieces by high compressive and shear forces under the extrusion ratio of 40-1.The ultimate tensile strength and elongation to failure increased with increasing the extrusion ratio.Recycled specimens with the extrusion ratio of 40:1 showed higher ultimate tensile strength of 342.61 MPa and higher elongation to failure of 11.32%,compared with those of the cast specimen.
文摘Separation of refined soybean oil/n-hexane miscellas was studied using different commercial ultra- and nanofiltration membranes, with cut-oil＇s in the range of 1 to 5 kDa and salt rejection higher than 97% （MgSO4）. Commercial soybean oil and n-hexane miscellas with 1：3 and 1：1 mass ratios were permeated in a dead-end module. The effects of the feed pressure （2-25 bar） on oil and n-hexane fluxes and rejection were investigated. Oil rejection ranged from negative values to 30.8%, soybean oil flux from 28.9 to 617.8 g/m2 hl and n-hexane flux from 8.5 to 1,078.5 g m2 hl. Membrane fouling was observed at all experimental conditions studied. The membrane separation process has proven to be a promising alternative to solvent recovery in soybean oil extraction.
