Papers by Author: Guo Qiang Xie

Abstract: We investigated the effects of addition elements (Sn, Al, Si, Ag, Fe, Cr) with a small amount on the glass-forming ability, thermal stability and mechanical properties of the Ti-Zr-Cu-Pd glassy alloy system. The results revealed that minor Sn addition improved the glass-forming ability, thermal stability and plasticity, Si addition enlarged the supercooled liquid region, and Fe addition improved the plasticity, while minor additions of Si, Ag, Fe, and Cr lowered the glass-forming ability, and Al and Cr additions were harmful to the plasticity of the Ti-Zr-Cu-Pd glassy alloy system.

Abstract: In recent years, bulk metallic glasses (BMGs) have received considerable attention due to their unique mechanical properties. However, the deformation of BMGs is highly localized in a few shear bands so that many of them exhibit poor plasticity. As such, more and more researchers have focused on improving the plasticity by in-situ or ex-situ introducing of nanoor micro-scale crystalline phases into the metallic glassy matrix in order to formation of multiple shear bands.

Abstract: Using the mixed powders containing gas-atomized powders of metallic glassy alloys (Cu₅₀Zr₄₅Al₅, Fe₇₃Si₇B₁₇Nb₃, Ni_52.5Nb₁₀Zr₁₅Ti₁₅Pt_7.5) blended with high-conductive Cu particulates, we produced bulk metallic glassy alloy composites with high strength and high electrical conductivity, as well as with enhanced plasticity and satisfying large size requirements by a spark plasma sintering process. In this paper we present and review our research results on the fabrication and properties of the bulk glassy alloy composites by the spark plasma sintering process.

Abstract: By using the Mg₆₅Zn₃₀Ca₅ amorphous powder prepared by ball-milling of the master alloy or its mixture powders, we produced Mg₆₅Zn₃₀Ca₅ bulk amorphous alloy and its composites by a spark plasma sintering process. The microstructure and corrosion properties of the prepared Mg₆₅Zn₃₀Ca₅ bulk amorphous alloy and its composites were investigated. The bulk amorphous alloy and its composites exhibited a high relative density and high corrosion resistance than commercial Mg alloys.

Abstract: Titanium (Ti) is one of the most widely used for biomaterials, because of its excellent anti-corrosion and high mechanical properties. In addion to these properies, the bioactivity of Ti is required. Recently, coating of the titanium dioxide (TiO₂) film on Ti plate surface is useful methods to obtain biocompatibility of Ti plate. If periodic nanostructures were formed on the film surface, direction of cell spreading might be controlled due to grooves direction. Then, femtosecond laser is one of the useful tools of periodic nanostructures formation. Peiriod of periodic nanostructures might be varied by changing the laser wavelength. In the experiments, the film was formed on Ti plate with an aerosol beam which was composed of submicron size TiO₂ particles and helium gas. The film was irradiated with the femtosecond laser. Laser wavelengths of the laser was at 1044, 775 and 388 nm, respectively. Periodic nanostructures, lying perpendicular to the laser electric field polarization vector, were formed on the film by femtosecond laser irradiation at 1044, 775 and 388 nm, respectively. The period of the periodic nanostructures on the film produced by femtosecond laser irradiation at 1044, 775 and 388 nm was about 350, 230 and 130 nm, respectively. In the cell test, cell spreading along the grooves of the periodic nanostructures was observed although it was not done for the film without the periodic nanostructures. These results suggested that direction of cell spreading could be controlled by the periodic nanostructures formation

Abstract: Using gas-atomized Ti-based metallic glassy powder, or the mixed powder blended with hydroxyapatite (HA) powder, we produced Ti-based bulk metallic glasses (BMGs) and the composites with high strength and satisfying large size requirements by a spark plasma sintering (SPS) process. The Ti-based BMGs and the composites with excellent properties and without toxic elements make it possible to apply as biomedical materials.

Abstract: The effects of small amounts of Si on the glass-forming ability, thermal stability and mechanical property of a TiZrCuPdSn bulk metallic glass were investigated. The addition of Si caused the decrease of glass-forming ability and the increase of the supercooled liquid (SCL) region. With 2 at.% Si addition, a significant SCL region of 80 K was obtained, which indicated high thermal stability of the glassy alloy and was in favor of secondary working by viscous flow deformation. With increasing Si content, the plasticity decreased.

Abstract: In this research, the effect of Ta addition on the formation, thermal stability and corrosion behavior of Ti-Zr-Cu-Pd bulk metallic glasses were investigated. The results revealed with minor addition of Ta, higher corrosion resistance and compressive strength as well as large plastic deformation were achieved. Minor addition Ta is effective for the formation of more protectively passive film during the process of anodic polarization. In addition, proper volume fraction nanoparticle with small size is responsible for the large plastic deformation of the as-cast Ti-based bulk metallic glasses with 1% Ta addition.

Abstract: Ti-based bulk metallic glasses with minor addition of Ag, Au or Pt elements were prepared by copper mold casting. The Microstructure of the as-cast samples was examined by TEM. Nanoparticles identified as cubic Pd3Ti with crystal planes of (111), (200), (220) and (311) are observed in all the alloys modified by the minor addition of Ag, Au or Pt. The results revealed that the glassy/nanoparticle composited alloys exhibited high strength about 2000 MPa and plastic strain between 1.5-10% due to the inhibition of propagation of shear band.

Abstract: Large-size Ni-based bulk metallic glass (BMG) composite samples exhibiting simultaneously high strength, enhanced plasticity and improved conductivity were produced by spark plasma sintering of mixed glassy powder blended with high-conductive Cu particulates. This opens new possibilities for the applications of the BMG composites as functional and structural materials.