Tungsten-Based Metallic Glasses with High Crystallization Temperature, High Modulus and High Hardness

Abstract

Ternary and quaternary tungsten-based alloys were melt-spun to produce metallic glasses having high crystallization temperature and high hardness. Alloy compositions were selected based on eutectic compositions of tungsten-based binary alloys; they are W 46 Ru 37 B 17 , W 54 Rh 26 B 20 , W 56 Ir 23 B 21 , etc. In most of the alloys, ductile metallic glasses were produced. DSC measurements showed that most of the metallic glasses undergo a two-step crystallization with the onset temperature of the first crystallization being as high as 1049$1298 K. Vickers hardness values at room temperature are 13$17 GPa. The ratio of the hardness H v to Young's modulus E satisfies the general rule for metallic glasses, i.

Effect of consolidation pressure on phase evolution during sintering of mechanically alloyed Al86Ni8Y6 amorphous powders via spark plasma sintering

“…Thus, a distribution of hardness and elastic modulus can clearly be observed, which resulted from the multi-phase microstructure with very hard intermetallic nano-precipitates and comparatively soft nanocrystalline Al distributed in the harder amorphous matrix. Calculated H/E ratio from different nanoindentation data points lies in the range of 0.045-0.065, which signifies the presence of amorphous matrix along with crystalline phases as this ratio for most of the bulk metallic glasses lies in the vicinity of $0.05 and increases with increasing crystalline phase fraction [41,42]. The present nanoindentation study is preliminary work in understanding the effect of various phase distribution in SPS sintered Al 86 Ni 8 Y 6 bulk amorphous alloy and detailed study is being carried out by the authors.…”

Micro and nano indentation studies on Zr60Cu10Al15Ni15 bulk metallic glass

“…The hardness (H) and elastic modulus (E) obtained from curve using Oliver-Pharr method [30] [31] which suggest H/E ratios for BMGs to be in range of 0.05~0.06.…”

Effects of tungsten contents on the microstructure, mechanical and anticorrosion properties of Zr–W–Ti thin film metallic glasses

“…The T x temperature values are in the ranges of 594.4 to 605.0°C and decrease with increasing W content. Compared to these rather high T g and T x temperature values of W-based W-Ru-B, W-Re-Ru-B BMGs [16,17] and W-Ni-B thin film metallic glass [18], the lower crystallization onset temperature values are obtained for the Zr-W-Ti TFMGs in this work. Meanwhile, the W-containing Zr-W-Ti TFMGs exhibit higher T x temperature values than those of Zr-based Zr-Ni-Al-Si TFMGs [6].…”

“…However, only limited studies on the W-based BMGs, such as W-Ru-B and W-Re-Ru-B metallic glasses are currently available [16,17]. The available data suggest that W-based BMGs have very high Young's modulus and hardness values as compared with the Zrbased BMG materials.…”