Nanocrystalline powders of Cu-Zn alloy in size ranging from 10 to 140nm was prepared from α-Cu-Zn alloy wire containing 39.8at.% Zn by an electrical explosion method. The particles are identified from x-ray diffracti...Nanocrystalline powders of Cu-Zn alloy in size ranging from 10 to 140nm was prepared from α-Cu-Zn alloy wire containing 39.8at.% Zn by an electrical explosion method. The particles are identified from x-ray diffraction as a mixture of the α,β,γ, and ε phases of Cu-Zn alloy. Most of the particles are hexagonal in shape, with only a small part being spherical and cubic. The composition of Zn in the explosion products varied from 6.9 to 45.2 at.% in different particles as determined by energy dispersive x-ray spectrometer. A possible mechanism for the formation of the alloy nanocrystalline powders is proposed, in which a redistribution process occurred caused by strong collision and diffusion between the two kinds of atoms during the powder formation.展开更多
Micro-grains of wurtzite boron nitride(wBN)crystal have been observed in the region of 5.0-7.0 GPa pressure and 1800-2000 K temperature where cubic boron nitride has been synthesized in the presence of a catalyst.The ...Micro-grains of wurtzite boron nitride(wBN)crystal have been observed in the region of 5.0-7.0 GPa pressure and 1800-2000 K temperature where cubic boron nitride has been synthesized in the presence of a catalyst.The wBN grain size is about 20-30nm.The presence of these micro-grains indicates that the pressure for wBN growth could be lower than that found in the previous work.展开更多
文摘Nanocrystalline powders of Cu-Zn alloy in size ranging from 10 to 140nm was prepared from α-Cu-Zn alloy wire containing 39.8at.% Zn by an electrical explosion method. The particles are identified from x-ray diffraction as a mixture of the α,β,γ, and ε phases of Cu-Zn alloy. Most of the particles are hexagonal in shape, with only a small part being spherical and cubic. The composition of Zn in the explosion products varied from 6.9 to 45.2 at.% in different particles as determined by energy dispersive x-ray spectrometer. A possible mechanism for the formation of the alloy nanocrystalline powders is proposed, in which a redistribution process occurred caused by strong collision and diffusion between the two kinds of atoms during the powder formation.
基金Supported by the Natinoal Natural Science Foundation of China under Grant No.69576012。
文摘Micro-grains of wurtzite boron nitride(wBN)crystal have been observed in the region of 5.0-7.0 GPa pressure and 1800-2000 K temperature where cubic boron nitride has been synthesized in the presence of a catalyst.The wBN grain size is about 20-30nm.The presence of these micro-grains indicates that the pressure for wBN growth could be lower than that found in the previous work.
