Influence of oxygen on the crystallization behavior of Zr65Cu27.5Al7.5 and Zr66.7Cu33.3 metallic glasses

Synthesis of bulk metallic glass composites using high oxygen containing Zr sponge

“…5c. It is also interesting to note the single crystallization peak in the DSC, which is characteristic of melts containing lower oxygen content [4]. This further illustrates the success of Y as an oxygen scavenger.…”

“…This is necessary to keep the oxygen content low as the transition metals are good oxide formers. Several investigators have explored the role of oxygen on the glass forming ability (GFA) and crystallization behavior of Zr-based glasses [1][2][3][4][5][6][7][8][9]. Oxide phases induce crystallization at higher temperatures and shorter incubation times [1].…”

“…These nanocrystals act as heterogeneous nucleation sites for the crystallization of other stable intermetallic phases. Murty et al [4] reported a two step crystallization process for melt spun ribbons with higher oxygen content as compared to a polymorphous crystallization of amorphous phase to Zr 2 (Cu, Al) at lower oxygen concentrations. Liu et al [6] has shown that oxygen level of 3000 ppm completely deteriorates the mechanical performance of the BMG and the microstructure contains predominantly crystalline phases.…”

Crystallization Behavior and Control of Amorphous Alloys

“…The dimensions and morphologies of the crystallization products strongly depend on the transformation mechanism, which is closely related to the chemical composition of the amorphous phase and to the thermodynamic properties of the corresponding crystalline phase. The crystallization products could include crystalline solids (solid solution, intermetallics, and/or compounds) (Foley et al, 1997;Kelton et al, 2003;Lu, 1996;Sahu et al, 2010;Zhang, et al, 2003) or quasicrystalline (Murty et al, 2000). As the crystallization process upon annealing of an amorphous phase is much slower than during solidification of liquids, it is relatively easier to fundamentally investigate crystallization in amorphous phases than in liquids on the processes of nucleation and growth, in particular of nucleation kinetics difficult to study quantitatively in the liquid state.…”

“…Therefore, oxygen contamination is of primary importance for the glass formation and crystallization behavior of Zr-based amorphous alloys. (Murty, et al, 2000), with permission from Elsevier. results showed that the T g increases with the addition of oxygen.…”