863 resultados para MAGNESIUM ALLOYS
Resumo:
We have measured photoluminescence of ZnSxTe1-x alloys (x > 0.7) at 300 K and under hydrostatic pressure up to 7 GPa. The spectra contain only a broad emission band under excitation of the 406.7 nm line. Its pressure coefficients are 47, 62 and 45 meV/GPa for x = 0.98, 0.92 and 0.79 samples, which are about 26%, 7% and 38% smaller than that of the band gap in the corresponding alloys. The Stokes shifts between emission and absorption of the bands were calculated by fitting the pressure dependence of the emission intensity, being 0.29, 0.48 and 0.13 eV for the three samples, respectively. The small pressure coefficient and large Stokes shift indicate that the emission band observed in our samples may correspond to the Te isoelectronic center in the ZnSxTe1-x alloy.
Geochemical salt translocation and the formation and characteristics of magnesium saline-alkalt soil
Resumo:
Mg-6Zn-5Al-4RE (RE = Mischmetal, mass%) alloy was prepared by metal mould casting method. The microstructure and mechanical properties of the as-cast and heat-treated alloys were investigated
Resumo:
Ti45Zr30Ni25Yx (x = 1, 3, 5 and 7) alloys were prepared by melt-spinning at wheel velocity of 20 m s(-1). The effect of additive Y on phase structure and electrochemical performance of melt-spun alloys was investigated. Ti45Zr30Ni25Yx melt-spun alloys were composed of I-phase and amorphous phase. T
Resumo:
Ti-based icosahedral quasicrystalline phase (I-phase) exhibited excellent hydrogen storage property for special structure. Unfortunately, the application as the negative electrode material of the nickel-metal hydride batteries was limited due to the poor electrochemical kinetics. Meanwhile, rare-earth element was beneficial to the electrochemical properties of Ti, Zr-based alloy.
Resumo:
The structure and electrochemical characteristics of melted composite Ti0.10Zr0.15V0.35Cr0.10Ni0.30+x% LaNi5 (x=0, 1, 5 and 10) hydrogen storage alloys have been investigated systematically. XRD shows that the matrix phase structure of V-based solid solution phase with a BCC structure and C14 Laves phase with hexagonal structure is not changed after adding LaNi5 alloy. However, the amount of the secondary phase increases with increasing LaNi5 content. Field emission scanning electron microscopy-energy dispersive spectroscopy (FESEM-EDS) shows that the C14 Laves phase contains more Zr and the white lard phase has a composition close to (Zr, Ti)(V, Cr, Ni, La)(2).