1 Introduction The use of chalcogenide alloys for optical data storage was first reported by S R. Ovshinsky in 1970. Research works dealt mostly with Te-based alloys because the Te-based media have high optical absorp...1 Introduction The use of chalcogenide alloys for optical data storage was first reported by S R. Ovshinsky in 1970. Research works dealt mostly with Te-based alloys because the Te-based media have high optical absorption, low thermal conductivity and adequate glass formation ability, such as TeGebS, TeSeGa, TeGeSnAu, TeGe, GeSb<sub>2</sub>Te<sub>4</sub> etc., of which GeSb<sub>2</sub>Te<sub>4</sub> com-展开更多
The bed expansion in the dense region of FCC turbulent fluidized bed has been studied in a cold fluidized bed made of plexiglass with 710×4000/870×ll000mm and a RFCC regenerator(800,000T／a）.By using dimens...The bed expansion in the dense region of FCC turbulent fluidized bed has been studied in a cold fluidized bed made of plexiglass with 710×4000/870×ll000mm and a RFCC regenerator(800,000T／a）.By using dimensional analysis,a calculation equation of dense phase density correlated by dimensionless groups is obtained.The equation may be use ful for process engineering design of commercial units.展开更多
The effect of the amount of Sn on the formation of fcc phase in Ti-13 Ta-x Sn(x=3,6,9 and 12,at.%)alloys was studied.The alloys were synthesized by mechanical alloying using a planetary mill,jar and balls of stabilize...The effect of the amount of Sn on the formation of fcc phase in Ti-13 Ta-x Sn(x=3,6,9 and 12,at.%)alloys was studied.The alloys were synthesized by mechanical alloying using a planetary mill,jar and balls of stabilized yttrium.Using Rietveld refinement,it was found that the obtained fcc phase has crystallite size smaller than 10 nm and microstrain larger than 10-3.Both conditions are required to form an fcc phase in Ti-based alloys.For all samples,the microstructure of the fcc phase consists of equiaxial crystallites with sizes smaller than 10 nm.The largest presence of fcc phase in the studied Ti alloy was found with 6 at.%Sn,because this alloy exhibits the largest microstrain(1.5×10-2)and crystallite size of 6.5 nm.Experimental data reveal that a solid solution and an amorphous phase were formed during milling.The necessary conditions to promote the formation of solid solution and amorphous phases were determined using thermodynamic calculations.When the amount of Sn increases,the energy required to form an amorphous phase varies from approximately 10 to approximately-5 k J/mol for 3 and 12 at.%Sn,respectively.The thermodynamic calculations are in agreement with XRD patterns analysis and HRTEM results.展开更多
So far,only two orientation relationships(OR)between hexagonal close-packed(HCP)(αphase)and facecentered cubic(FCC)structures in zirconium and titanium alloys have been reported.Here a new type FCC phase(named γ pha...So far,only two orientation relationships(OR)between hexagonal close-packed(HCP)(αphase)and facecentered cubic(FCC)structures in zirconium and titanium alloys have been reported.Here a new type FCC phase(named γ phase)with OR:<11■0>_(α)‖<100>_(γ) and{0001}_(α)‖{002}_(γ) was observed for the first time in annealed pure zirconium by means of transmission electron microscopy(TEM)technique.The α→γ phase transformation can be accomplished via expansion along[1■00]direction and slip of Shockley partial dislocation with 1/3[1■00]on(0001)basal planes.展开更多
文摘1 Introduction The use of chalcogenide alloys for optical data storage was first reported by S R. Ovshinsky in 1970. Research works dealt mostly with Te-based alloys because the Te-based media have high optical absorption, low thermal conductivity and adequate glass formation ability, such as TeGebS, TeSeGa, TeGeSnAu, TeGe, GeSb<sub>2</sub>Te<sub>4</sub> etc., of which GeSb<sub>2</sub>Te<sub>4</sub> com-
文摘The bed expansion in the dense region of FCC turbulent fluidized bed has been studied in a cold fluidized bed made of plexiglass with 710×4000/870×ll000mm and a RFCC regenerator(800,000T／a）.By using dimensional analysis,a calculation equation of dense phase density correlated by dimensionless groups is obtained.The equation may be use ful for process engineering design of commercial units.
基金financial support from FONDECYT Project No.1190797FONDEQUIP/EQM Project No.140095。
文摘The effect of the amount of Sn on the formation of fcc phase in Ti-13 Ta-x Sn(x=3,6,9 and 12,at.%)alloys was studied.The alloys were synthesized by mechanical alloying using a planetary mill,jar and balls of stabilized yttrium.Using Rietveld refinement,it was found that the obtained fcc phase has crystallite size smaller than 10 nm and microstrain larger than 10-3.Both conditions are required to form an fcc phase in Ti-based alloys.For all samples,the microstructure of the fcc phase consists of equiaxial crystallites with sizes smaller than 10 nm.The largest presence of fcc phase in the studied Ti alloy was found with 6 at.%Sn,because this alloy exhibits the largest microstrain(1.5×10-2)and crystallite size of 6.5 nm.Experimental data reveal that a solid solution and an amorphous phase were formed during milling.The necessary conditions to promote the formation of solid solution and amorphous phases were determined using thermodynamic calculations.When the amount of Sn increases,the energy required to form an amorphous phase varies from approximately 10 to approximately-5 k J/mol for 3 and 12 at.%Sn,respectively.The thermodynamic calculations are in agreement with XRD patterns analysis and HRTEM results.
文摘So far,only two orientation relationships(OR)between hexagonal close-packed(HCP)(αphase)and facecentered cubic(FCC)structures in zirconium and titanium alloys have been reported.Here a new type FCC phase(named γ phase)with OR:<11■0>_(α)‖<100>_(γ) and{0001}_(α)‖{002}_(γ) was observed for the first time in annealed pure zirconium by means of transmission electron microscopy(TEM)technique.The α→γ phase transformation can be accomplished via expansion along[1■00]direction and slip of Shockley partial dislocation with 1/3[1■00]on(0001)basal planes.
