Oxidation Behavior of a Pd43Cu27Ni10P20 Bulk Metallic Glass and Foam in Dry Air

Abstract

The oxidation behavior of both Pd 43 Cu 27 Ni 10 P 20 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 (k p values) generally increased with temperature. It was found that the oxidation k p 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 Pd

Sub-second thermoplastic forming of bulk metallic glasses by ultrasonic beating

“…Here, the key issue would be how to avoid oxidation and crystallization during the essential high temperature treatment13. As two dynamic processes, oxidation and crystallization are strongly effected by the holding time at high temperature3637, i. e., the two adverse factors for thermoplastic forming of BMGs can be weakened to the most extent if the processing time (See Fig. 1) could be as short as possible.…”

Surface Modification of the Bulk Metallic Glass Zr$_{46}$Cu$_{36.8}$Ag$_{9.2}$Al$_8$ Triggered by Millisecond Laser Irradiation

“…The fitting by peak position and intensity identified Zr 2 Cu, Zr 7 Cu 10 , ZrO 2 and ZrO crystallines. The latter two are typically formed during oxidation of zirconium amorphous alloys [37,38].…”

Controllable nanoimprinting of metallic glasses: effect of pressure and interfacial properties

“…Integrating equation (28) from the initial time t min (i.e., the time where the filling of a pore at the position r begins) to the final time T yields…”

“…Since Pd-BMG is prone to oxidation [28], we hypothesize that this additional factor is the formation of a rigid oxide layer on the BMG surface (i.e., the layer must be broken before the BMG starts flowing into the pore). The above conjecture is confirmed by a direct comparison of the experimentally determined filling ratio with the analytical results derived in section 5.1.…”