The thixotropic behavior of semi-solid AZ91D slurry was studied through a Couette type viscometer. The results show that the apparent viscosity of semi-solid AZ91D magnesium alloy slurry increases after being isotherm...The thixotropic behavior of semi-solid AZ91D slurry was studied through a Couette type viscometer. The results show that the apparent viscosity of semi-solid AZ91D magnesium alloy slurry increases after being isothermally held, but the apparent viscosity quickly falls down to a steady state value after being stirred again and it takes on a sharp shear-thinning behavior. With the same shearing rate and the rest time increasing, the steady apparent viscosity increases because of the agglomeration of the solid particles, and the time required for the slurry to reach the steady state also becomes longer. If the solid fraction increases, it takes longer time for the slurry to reach the steady apparent viscosity with the same shearing rate and the same rest time. If the solid fraction and the rest time are the same, but the shearing rate rises, it takes shorter time for the slurry to reach the steady apparent viscosity and the final steady apparent viscosity also decreases.展开更多
Compression tests on semi-solid SiCp/AZ61 magnesium matrix composites were carried out using Thermecmastor-Z dynamic material testing machine.Influences of strain-rate,strain,temperature and volume fraction of SiC par...Compression tests on semi-solid SiCp/AZ61 magnesium matrix composites were carried out using Thermecmastor-Z dynamic material testing machine.Influences of strain-rate,strain,temperature and volume fraction of SiC particles on flow stress were analyzed.The results show that the flow stress of semi-solid SiCp/AZ61 composites is sensitive to temperature and strain rate.The lower the temperature and the larger the strain rate,the higher the flow stress.Meanwhile the flow stress increases with the increase of the volume fraction of SiC particles.This study helps establish the constitutive model of magnesium matrix composites and offers theoretic and experimental references for its thixoforming.展开更多
The rheology of magnesium oxychloride cement (MOC) was presented. The rheological properties and thixotropic behaviors of the MOC pastes were determined with a rotating viscometer. The results have showed significant ...The rheology of magnesium oxychloride cement (MOC) was presented. The rheological properties and thixotropic behaviors of the MOC pastes were determined with a rotating viscometer. The results have showed significant difference between the MOC and portland cement in terms of their rheological behaviors. The yield stress and plastic viscosity of the MOC pastes are much larger than those of portland cement pastes. Therefore, the MOC has a better cohesive property.展开更多
文摘The thixotropic behavior of semi-solid AZ91D slurry was studied through a Couette type viscometer. The results show that the apparent viscosity of semi-solid AZ91D magnesium alloy slurry increases after being isothermally held, but the apparent viscosity quickly falls down to a steady state value after being stirred again and it takes on a sharp shear-thinning behavior. With the same shearing rate and the rest time increasing, the steady apparent viscosity increases because of the agglomeration of the solid particles, and the time required for the slurry to reach the steady state also becomes longer. If the solid fraction increases, it takes longer time for the slurry to reach the steady apparent viscosity with the same shearing rate and the same rest time. If the solid fraction and the rest time are the same, but the shearing rate rises, it takes shorter time for the slurry to reach the steady apparent viscosity and the final steady apparent viscosity also decreases.
基金Projects (50765005,50465003) supported by the National Natural Science Foundation of ChinaProject (S00875) supported by Innovative Group of Science and Technology of College of Jiangxi Province,China
文摘Compression tests on semi-solid SiCp/AZ61 magnesium matrix composites were carried out using Thermecmastor-Z dynamic material testing machine.Influences of strain-rate,strain,temperature and volume fraction of SiC particles on flow stress were analyzed.The results show that the flow stress of semi-solid SiCp/AZ61 composites is sensitive to temperature and strain rate.The lower the temperature and the larger the strain rate,the higher the flow stress.Meanwhile the flow stress increases with the increase of the volume fraction of SiC particles.This study helps establish the constitutive model of magnesium matrix composites and offers theoretic and experimental references for its thixoforming.
文摘The rheology of magnesium oxychloride cement (MOC) was presented. The rheological properties and thixotropic behaviors of the MOC pastes were determined with a rotating viscometer. The results have showed significant difference between the MOC and portland cement in terms of their rheological behaviors. The yield stress and plastic viscosity of the MOC pastes are much larger than those of portland cement pastes. Therefore, the MOC has a better cohesive property.
