The phase transitions in Pd40Ni10Cu30P20 bulk metallic glass (BMG) have been studied under high pressure and high temperature (HP & HT) by X-ray diffraction measurements with synchrotron radiation source. We found...The phase transitions in Pd40Ni10Cu30P20 bulk metallic glass (BMG) have been studied under high pressure and high temperature (HP & HT) by X-ray diffraction measurements with synchrotron radiation source. We found that the BMG underwent a phase transitions of amorphous-crystalline-amorphous at 10 GPa upon heating. The parallel experiments were carried out at 7 GPa, while we did not observe the amorphous-crystalline-amorphous transitions by increasing temperature. Quenching the melted BMG at 7 GPa, it was found that the phase crystallized from the melt differed from the primary phase crystallized from the starting amorphous solid upon heating, suggesting there existed a distinct mechanism in two cases.展开更多
Ti/Zr-based icosahedral quasicrystals are a kind of promising hydrogen storage ma- terials, however their absorption regeneration after oxidation-poisoning has been scarcely studied. This work is intended to investiga...Ti/Zr-based icosahedral quasicrystals are a kind of promising hydrogen storage ma- terials, however their absorption regeneration after oxidation-poisoning has been scarcely studied. This work is intended to investigate the deuterium-storage re- generation of a suction-cast Ti36Zr40Ni20Pd4 quasicrystal. It was found that only through hot vacuuming the quasicrystal could be refreshed from air-flow poisoning to absorb deuterium in two cycles. During the first absorption course, a pregnancy period was observed before the real deuterium uptake while deuterium was loaded rapidly during the second one. The deuterium concentration in the alloy can reach 0.011 mol.D2/(g.M) (corresponding to a hydrogen mass percent of 2.2%. D2 and M denote molecular deuterium and the metallic alloy). But the loaded deuterium was very difficult to release completely even by eight-stage desorption at different tem- peratures. After the second desorption, the quasicrystal phase remained in a small volume, as though the desorption temperature was beyond the crystallization temperature of the quasicrystal. This probably is attributed to the solution function of residual deuterium in the alloy.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.10299041 and 5057111).
文摘The phase transitions in Pd40Ni10Cu30P20 bulk metallic glass (BMG) have been studied under high pressure and high temperature (HP & HT) by X-ray diffraction measurements with synchrotron radiation source. We found that the BMG underwent a phase transitions of amorphous-crystalline-amorphous at 10 GPa upon heating. The parallel experiments were carried out at 7 GPa, while we did not observe the amorphous-crystalline-amorphous transitions by increasing temperature. Quenching the melted BMG at 7 GPa, it was found that the phase crystallized from the melt differed from the primary phase crystallized from the starting amorphous solid upon heating, suggesting there existed a distinct mechanism in two cases.
基金supported by Science and Technology Development Foundation of China Academy of Engineering Physics (No.2007A07002)
文摘Ti/Zr-based icosahedral quasicrystals are a kind of promising hydrogen storage ma- terials, however their absorption regeneration after oxidation-poisoning has been scarcely studied. This work is intended to investigate the deuterium-storage re- generation of a suction-cast Ti36Zr40Ni20Pd4 quasicrystal. It was found that only through hot vacuuming the quasicrystal could be refreshed from air-flow poisoning to absorb deuterium in two cycles. During the first absorption course, a pregnancy period was observed before the real deuterium uptake while deuterium was loaded rapidly during the second one. The deuterium concentration in the alloy can reach 0.011 mol.D2/(g.M) (corresponding to a hydrogen mass percent of 2.2%. D2 and M denote molecular deuterium and the metallic alloy). But the loaded deuterium was very difficult to release completely even by eight-stage desorption at different tem- peratures. After the second desorption, the quasicrystal phase remained in a small volume, as though the desorption temperature was beyond the crystallization temperature of the quasicrystal. This probably is attributed to the solution function of residual deuterium in the alloy.