A constitutive equation was proposed to describe the effect of grain size on the deformation behavior.And a coupling simulation of deformation with heat transfer and microstructure was carried out in isothermal upsett...A constitutive equation was proposed to describe the effect of grain size on the deformation behavior.And a coupling simulation of deformation with heat transfer and microstructure was carried out in isothermal upsetting process of Ti60 alloy.The effects of processing parameters on the equivalent strain,the equivalent stress,the temperature rise and the grain size distribution in isothermal upsetting process of Ti60 alloy were analyzed.It is concluded that the uniformity of equivalent strain and equivalent stress increases with the increase of deformation temperature.However,the temperature rise and the grain size decreases with the increase of deformation temperature.The non-uniformity of equivalent strain,equivalent stress,temperature field and grain size increases with the increase of height reduction.And the calculated grain size using simulation is in good agreement with the experimental one.展开更多
The effect of particle size of silica, as catalyst binder, on the chemical and mechanical properties of iron based FT catalyst was studied in this work. The samples were characterized using XRD, BET, TEM, FT-IR, and H...The effect of particle size of silica, as catalyst binder, on the chemical and mechanical properties of iron based FT catalyst was studied in this work. The samples were characterized using XRD, BET, TEM, FT-IR, and H2-TPR, re- spectively. The attrition resistance and the FT activity were tested. Si-8-Si-15 catalysts prepared with 8-15 nm silica sol show good attrition resistance （attrition loss 〈 4%）, especially Si-13 with an attrition loss of 1.89%. He- matite appeared in XRD patterns when silica sol above 15 nm is used. TEM micrographs show that no obvious SiO2 particles appear when silica sol particle with size less than 8 nm was used, but SiO2 particles coated with small ferrihydrite particles appear when silica sol above 8 nm was used. Si-O-Si vibration peak in FT-IR spectra increases with increasing silica sol size. Samples prepared with silica sol show good stability of FT reactions, and the average molecular weight of FT products increases with the increase of SiO2 particle.展开更多
基金Project(KP200905) supports by the Fund of the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University,China
文摘A constitutive equation was proposed to describe the effect of grain size on the deformation behavior.And a coupling simulation of deformation with heat transfer and microstructure was carried out in isothermal upsetting process of Ti60 alloy.The effects of processing parameters on the equivalent strain,the equivalent stress,the temperature rise and the grain size distribution in isothermal upsetting process of Ti60 alloy were analyzed.It is concluded that the uniformity of equivalent strain and equivalent stress increases with the increase of deformation temperature.However,the temperature rise and the grain size decreases with the increase of deformation temperature.The non-uniformity of equivalent strain,equivalent stress,temperature field and grain size increases with the increase of height reduction.And the calculated grain size using simulation is in good agreement with the experimental one.
基金financial support from Shenhua Group and Zhejiang University of Technology is highly acknowledged for the catalyst test
文摘The effect of particle size of silica, as catalyst binder, on the chemical and mechanical properties of iron based FT catalyst was studied in this work. The samples were characterized using XRD, BET, TEM, FT-IR, and H2-TPR, re- spectively. The attrition resistance and the FT activity were tested. Si-8-Si-15 catalysts prepared with 8-15 nm silica sol show good attrition resistance （attrition loss 〈 4%）, especially Si-13 with an attrition loss of 1.89%. He- matite appeared in XRD patterns when silica sol above 15 nm is used. TEM micrographs show that no obvious SiO2 particles appear when silica sol particle with size less than 8 nm was used, but SiO2 particles coated with small ferrihydrite particles appear when silica sol above 8 nm was used. Si-O-Si vibration peak in FT-IR spectra increases with increasing silica sol size. Samples prepared with silica sol show good stability of FT reactions, and the average molecular weight of FT products increases with the increase of SiO2 particle.
