Papers by Keyword: BMG Composite

Abstract: An In-situ Mg-based bulk metallic glass (BMG) composite containing 40% volume fraction of Mg-rich crystalline flakes was produced by die casting. During cooling from the melt, the flakes nucleate heterogeneously and subsequently grow with their broad faces parallel to the {0001} plane. This generated a uniform dispersion of randomly-oriented flakes within an amorphous matrix. When compressed uniaxially up to 60% reduction in the supercooled liquid (SCL) region, the flakes in this composite were substantially aligned their broad faces towards the compression plane that generated a strong //ND fibre texture.

Abstract: Bulk metallic glasses (BMGs) and high entropy alloys (HEAs) have unique structures at the length scales of micro- and nano-metre, and exhibit unique properties, which make them potential materials for structural applications. The tensile ductility of dendrite/BMG composites can be greatly improved by Bridgman solidification. The BCC structured HEA with a composition of Ti0.5AlCoCrFeNi exhibits ultrahigh fracture strength which is competitive to most of the BMGs, moreover, the strength can be sustained at high temperatures. The phase changes of HEAs are closely related to the atomic packing efficiency (APE).

Abstract: The thermal properties of a Zr76.11Ti4.20Cu4.51Ni3.16Be1.49Nb10.53 bulk metallic glass (BMG) have been investigated by using a differential scanning calorimeter (DSC). The composition of dendrite phase was then subsequently analyzed by using an EPMA, XRD, and TEM. The glass transition and crystallization onset temperatures were determined as 339.7 °C and 375.8 °C for this BMG, respectively. The Zr-Ti-Nb dendrite phase was found to have a BCC structure. Mechanical properties have also been examined by conducting a series of uniaxial compression tests at various temperatures within supercooled liquid region under the strain rates between 10-4 /s and 3×10-2 /s. The hardness of matrix and dendrite was then measured separately. The glassy matrix appears to play major role on the elongation, while dendrite phase on the strength of this BMG composite at high temperatures within supercooled liquid region.