Papers by Author: Xin Lin Wang

Abstract: Co-free AB5-type LaxMm1-x(NiMnSiAlFe)4.9 (x = 0, 0.45, 0.75, 1) hydrogen storage alloys were prepared by casting and rapid quenching. The phase structures and microstructures of the as-cast and quenched alloys were analyzed and observed by XRD and SEM. The electrochemical performances of the as-cast and quenched alloys were measured. The effects of La content and quenching rate on the microstructures and electrochemical properties of the alloys were investigated comprehensivel y. The obtained results indicate that the Co-free AB5-type hydrogen storage alloy with excellent synthetical electrochemical performances can be prepared by adjusting La content and employing appropriate rapid quenching technique.

Abstract: A composite of needle-like nano-hydroxyapatite (n-HA)/poly (D,L) lactide (PDLLA) was prepared. The n-HA crystals were poorly crystallized and uniformly distributed in the composite with a crystal size of 10–20 nm in diameter by 40–60nm in length，which was smaller than that of pure nano-HA. Molecular interactions and chemical bonds might present between n-HA and PDLLA in the composite, which were revealed by IR and XPS. The synthetic n-HA/PDLLA composite had a good homogeneity and could be a bioactive material for bone defect especially for load-bearing bone repair, which is more potential than pure HA or pure PDLLA.

Abstract: Employing the first principles discrete variational method(DVM), we investigated the electronic structure of LaNi5 hydrogen storage alloys containing various alloying elements, M=Mn,Fe,Co. The results showed that s electrons of H mainly interact with s electrons of hydride-non-forming element Ni, though hydride forming element La have stronger affinity to hydrogen atom. And alloying elements strengthened the bond between B-H, so decreased the capacity of doped-system.

Abstract: The characteristics of microstructures, martensitic transition, and magnetic field- induced strains of melt-spun ribbons are reviewed. The preferential alignment of crystal grains in the spun ribbons depends not only on the composition, but also on the spinning velocity. The increase of spinning velocity decreases the temperature of martensitic transition and decreases the enthalpy change. The anisotropies and retardance of field-induced strains was discussed, especially for the influence of the texture and annealing of the ribbons.

Abstract: FeCuNbSiB and FeZrBCu nanocrystalline ribbons can be obtained directly through the melt- spinning technique without additional annealing processes. The giant magnetoimpedance can be observed in FeCuNbSiB and FeZrBCu as quenched ribbons. The addition of Cu improves the nano-crystallization of a-Fe(Si) or a-Fe phase and reduces the grain size in FeCuNbSiB and FeZrBCu as quenched ribbons, which enhances the magnetoimpedance via increasing the variation of permeability under fields. The present experimental results reveal a novel route to fabricate the Fe based nanocrystalline soft magnetic materials with giant magnetoimpedance effect.

Abstract: A non-stoichiometric polycrystalline Ni50Mn27Ga23 magnetic shape memory alloy was prepared by melt-spinning technology. The effects of melt-spinning on the martensitic transformation and magnetic-field-induced strain (MFIS) of the melt-spun ribbon were investigated. The experimental results show that the melt-spun ribbon undergoes the thermal-elastic martensitic transformation and exhibits the thermo-elastic shape memory effect. But the martensitic transformation temperature decreases and Curie temperature remains unchanged. A particular internal stress induced by melt-spinning made a texture structure in the melt-spun ribbon, which made the melt-spun ribbon obtain larger transition-induced strain and MFIS. The internal stress was released under cycling of magnetic field. This resulted in a decrease of MFIS of the melt-spun ribbon.