Oxidation Behavior of a Pd43Cu27Ni10P20 Bulk Metallic Glass and Foam in Dry Air
نویسنده
چکیده
The oxidation behavior of both Pd43Cu27Ni10P20 bulk metallic glass (Pd4-BMG) and its amorphous foam containing 45 pct porosity (Pd4-AF) was investigated over the temperature range of 343 K (70 C) to 623 K (350 C) in dry air. The results showed that virtually no oxidation occurred in the Pd4-BMG at T< 523 K (250 C), revealing the alloy’s favorable oxidation resistance in this temperature range. In addition, the oxidation kinetics at T ‡ 523 K (250 C) followed a parabolic-rate law, and the parabolic-rate constants (kp values) generally increased with temperature. It was found that the oxidation kp values of the Pd4-AF are slightly lower than those of the Pd4-BMG, indicating that the porous structure contributes to improving the overall oxidation resistance. The scale formed on the alloys was composed exclusively of CuO at T ‡ 548 K (275 C), whose thickness gradually increased with increasing temperature. In addition, the amorphous structure remained unchanged at T £ 548 K (275 C), while a triplex-phase structure developed after the oxidation at higher temperatures, consisting of Pd2Ni2P, Cu3P, and Pd3P.
منابع مشابه
An explanation of the differences in diffusivity of the components of the metallic glass Pd43Cu27Ni10P20.
Bartsch et al. [Phys. Rev. Lett. 104, 195901 (2010)] reported measurements of the diffusivities of different components of the multi-component bulk metallic glass Pd43Cu27Ni10P20. The diffusion of the largest Pd and the smallest P was found to be drastically different. The Stokes-Einstein relation breaks down when considering the P constituent atom, while the relation is obeyed by the Pd atom o...
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