The ordering of the α-Fe(Si) crystallization phase in annealed Fe73.5Cu1Mo3Si13.5B9 alloy has been studied using XRD method. The α-Fe(Si) phase in Fe73.5Cu1Mo3Si13.5B9 alloy annealed at 460℃ for 1 h consists of th...The ordering of the α-Fe(Si) crystallization phase in annealed Fe73.5Cu1Mo3Si13.5B9 alloy has been studied using XRD method. The α-Fe(Si) phase in Fe73.5Cu1Mo3Si13.5B9 alloy annealed at 460℃ for 1 h consists of the DO3-type ordered region with spherical shape and disordered region. The size of DO3 ordered region increases with the annealing temperature. When the annealing temperature is 560℃, the size of the ordered region in the α-Fe(Si) grain is 14.0nm,which is nearly as large as that of the α-Fe(Si) grain (14.2 nm) and the degree of order of the α-Fe(Si) phase is about 0.78. When Fe73.5Cu1 Mo3Si13.5B9 amorphous alloy is annealed at 520℃， with the increment of the annealing time, the shape of the DO3 ordered region in the α-Fe(Si) phase is spheroidal at the beginning of the annealing and becomes spherical and has asize of 12.8 nm when the annealing time is 60 min. In addition, the DO3 superlattice lines of the α-Fe(Si) phase will vanish if Fe73.5Cu1Mo3Si13.5 B9 amorphous alloy is annealed for 1 h at 750℃.展开更多
The microstructure and the stability of Fe_73.5Cu_1Nb_3Si_13.5B_9 alloy at different stages of phase transformation were investigated through the observation of X-ray difraction and transmission electron microscopy an...The microstructure and the stability of Fe_73.5Cu_1Nb_3Si_13.5B_9 alloy at different stages of phase transformation were investigated through the observation of X-ray difraction and transmission electron microscopy and the measurement of magnetic aftereffect (MAE). It was found that the dependence of the volume fraction of amorphous phase and the MAE in the samples annealed from 450 to 700℃ on the annealing temperature is similar.展开更多
The relationship between the activity and the precursor phase composition of the molten iron catalyst for ammonia synthesis has been studied with high pressure testing equipment and XRD. A humped curve between the act...The relationship between the activity and the precursor phase composition of the molten iron catalyst for ammonia synthesis has been studied with high pressure testing equipment and XRD. A humped curve between the activity and Fe2+/Fe3+ has been obtained. It is found that the unicity of the iron oxidate phase in precursor is an essential condition of the high activity of the iron catalyst and that the uniform distribution of the adominant phase and the promoters is the key to preparing a catalyst with better performance The humped curve is interpreted using the ratio f of the phase compositions in precursor. A new idea has been obtained that the activity change of the molten iron catalyst depends essentially on the molecule ratio of the different iron oxidates in precursor under the certain promoters, and it is found that the FeO based catalyst for ammonia synthesis with Wustite phase structure (Fe1-xO, 0.04≤x≤0.10) has the highest activity of all the molten iron catalysts for ammonia synthesis.展开更多
文摘The ordering of the α-Fe(Si) crystallization phase in annealed Fe73.5Cu1Mo3Si13.5B9 alloy has been studied using XRD method. The α-Fe(Si) phase in Fe73.5Cu1Mo3Si13.5B9 alloy annealed at 460℃ for 1 h consists of the DO3-type ordered region with spherical shape and disordered region. The size of DO3 ordered region increases with the annealing temperature. When the annealing temperature is 560℃, the size of the ordered region in the α-Fe(Si) grain is 14.0nm,which is nearly as large as that of the α-Fe(Si) grain (14.2 nm) and the degree of order of the α-Fe(Si) phase is about 0.78. When Fe73.5Cu1 Mo3Si13.5B9 amorphous alloy is annealed at 520℃， with the increment of the annealing time, the shape of the DO3 ordered region in the α-Fe(Si) phase is spheroidal at the beginning of the annealing and becomes spherical and has asize of 12.8 nm when the annealing time is 60 min. In addition, the DO3 superlattice lines of the α-Fe(Si) phase will vanish if Fe73.5Cu1Mo3Si13.5 B9 amorphous alloy is annealed for 1 h at 750℃.
基金National Natural &ience Foundation of China!(No. 59671020).
文摘The microstructure and the stability of Fe_73.5Cu_1Nb_3Si_13.5B_9 alloy at different stages of phase transformation were investigated through the observation of X-ray difraction and transmission electron microscopy and the measurement of magnetic aftereffect (MAE). It was found that the dependence of the volume fraction of amorphous phase and the MAE in the samples annealed from 450 to 700℃ on the annealing temperature is similar.
基金Project supported by the Provincial Natural Science Foundation of Zhejiang.
文摘The relationship between the activity and the precursor phase composition of the molten iron catalyst for ammonia synthesis has been studied with high pressure testing equipment and XRD. A humped curve between the activity and Fe2+/Fe3+ has been obtained. It is found that the unicity of the iron oxidate phase in precursor is an essential condition of the high activity of the iron catalyst and that the uniform distribution of the adominant phase and the promoters is the key to preparing a catalyst with better performance The humped curve is interpreted using the ratio f of the phase compositions in precursor. A new idea has been obtained that the activity change of the molten iron catalyst depends essentially on the molecule ratio of the different iron oxidates in precursor under the certain promoters, and it is found that the FeO based catalyst for ammonia synthesis with Wustite phase structure (Fe1-xO, 0.04≤x≤0.10) has the highest activity of all the molten iron catalysts for ammonia synthesis.
