ScholarWorks@숙명여자대학교

초록

Stable bulk glass forming alloys can be developed over a wide range of compositions in Cu-Hf-Al ternary systems starting from the Cu49Hf42Al9 bulk metallic glass. Ternary Cu-Hf-Al alloys can be cast directly from the melt into copper molds to form fully amorphous strips with thicknesses of 1. to 6 mm. The maximum critical diameter of the new Cu-Hf-Al ternary alloy was 6 mm. X-ray diffraction patterns were used to confirm the amorphous nature of the ternary Cu-Hf-Al alloys. To increase the toughness of these metallic glasses, we reinforced the Cu48Hf43Al9 bulk metallic glass-forming liquid with a 50% volume fraction of tungsten particles and an 80% volume fraction of tungsten wires with diameters of 242.4 mu m. Composites with a critical diameter of 7 nun and length 70 min were synthesized. The Structure of the composites was confirmed by using X-ray diffraction (XRD), and the scanning electron microscopy (SEM). The mechanical properties of the composites were studied in compression tests. The thermal stability and the crystallization processes of the Cu-Hf-Al alloys and composites were investigated by using differential scanning calorimetry, (DSC). Values of the glass transition temperature (T,), the crystallization temperature (T-x), and the supercooled liquid region (Delta T = T-x - T-g) are given in this paper.

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