Papers by Keyword: Metallic Glass Powders

Abstract: In this work, Cu₅₀Zr₄₃Al₇ metallic glass powders were produced by gas atomization method. The structure and crystallization characteristics of the as-prepared powders with different particle size distributions were studied in detail. The amorphous state of the alloy powders was confirmed by X-ray diffraction (XRD), in which amorphous phase formed. The scanning election microscopy (SEM) result showed that the selected metallic glass powder performed excellent owned good spherical morphology, which was also observed on an optical microscope (OM). At the same time, the particle size distributions ranging from 20 μm to 200 μm of as-prepared metallic glass powders were determined by laser diffraction. Moreover, the crystallization behavior of the Cu₅₀Zr₄₃Al₇ metallic glass powders was investigated by differential scanning calorimetry (DSC).

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: In this paper both electric discharge assisted milling [1, 2] and conventional mechanosynthesis techniques were applied to investigate the effects of milling conditions on the fracture and agglomeration of amorphous CoSiB ribbons produced by planar flow casting. The effect of spark energy on particle shape and size produced by discharge milling was studied. Conventional milling in inert atmosphere for extended periods generally leads to the formation of porous powder particle aggregates, each particle comprised of small amorphous or, after extended milling times, nanocrystalline elements. The mechanism of agglomeration was believed to originate from repeated fracture, deformation and cold welding of individual ribbon elements. In contrast to conventional milling, spark discharge milling was found to induce the formation of predominantly sub-micron single particles of amorphous powder. The morphology of individual particles varied from sub-micron irregular shaped particles to remelted particles, depending on selection of vibrational amplitude during discharge. For high vibrational amplitudes and high energy input a wider range of particles as produced. These included sub-micron particles, remelted particles and welded agglomerates, and nano-sized particles produced as a fume and collected during discharge milling under flowing argon. These results combined with observations that most re-melted particles produced by discharge milling were also amorphous confirmed that extremely high heating and cooling rates are associated with discharge milling of metals. They also confirm the potential of electrical discharge milling as a new route for the synthesis of ultrafine and nanosized powder particles from amorphous ribbon, for possible processing into 3-D shapes.