Synthesis of Cu₄₇Ti₃₄Zr₁₁Ni₈Bulk Metallic Glass by Warm Extrusion of Gas Atomized Powders

Abstract

Cu 47 Ti 34 Zr 11 Ni 8 amorphous gas atomized powders were consolidated by warm extrusion. After consolidation near 723 K using an extrusion ratio of 5, the material retains between 88% and 98% of the amorphous structure found in the gas atomized powder. The onsets of the glass transition and crystallization temperatures of this extruded material are observed respectively at slightly higher and lower temperatures than those of the starting powders. These temperature shifts are attributed to a composition change in the remaining amorphous phase during partial devitrification throughout the extrusion process. Powders extruded at the same temperature, but using higher extrusion ratios of 9 and 13, exhibit substantial devitrification during the consolidation process yet still deform homogeneously.

Cold sprayed aluminum based glassy coating: Synthesis, wear and corrosion properties

“…A C C E P T E D M A N U S C R I P T synthesized using high pressure gas atomization route [40]. Pure elements were first melted in a graphite crucible under argon atmosphere.…”

“…Subsequently, the melt was poured into an argon gas stream for atomization. The details of the powder synthesis can be found elsewhere [40].…”

Crystallization Behavior and Control of Amorphous Alloys

“…This opens up the possibility of preparing truly bulk samples through powder consolidation in supercooled liquid region. In the Zr-, Cu-, Fe-and Ni-based alloy systems, some successful consolidation of amorphous powders with wide supercooled liquid region has been achieved by warm extrusion, spark plasma sintering and equal channel angular pressing (ECAP) (Choi et al, 2007;Ishihará et al, 2002;Itoi et al, 2001;Karaman et al, 2004;Kawamura et al, 1997;Kim et al, 2004;Kim et al, 2009;Lee et al, 2003;Mear et al, 2009;Robertson et al, 2003;Senkov et al, 2004;Senkov et al, 2005;Sordelet et al, 2002;Zhang et al, 2006b;Zhang, et al, 2007a). The consolidated samples show almost the same thermal properties, mechanical properties, and/or soft magnetic properties as those of the BMGs prepared by direct melt casting from molted The data of the onset temperature of crystallization (T x ) and the glass transition temperature (T g ) at the heating rate of 0.67 K s -1 are also shown.…”

Deformation-induced crystallization and amorphization of Al-based metallic glasses

“…Current efforts to produce bulk amorphous Al alloys focus mainly on the compaction and extrusion of amorphous, atomized powders [4,5]. In many cases the deformation of amorphous phases was observed to yield a crystallization reaction, for example upon cold-rolling of AI-Y-Fe and Al-Sm based amorphous ribbons [6], upon bending of different Al-based amorphous ribbons [7], warm-extrusion of gas-atomized amorphous powders [4,5] if the extrusion ratio exceeds a critical value or nanoindentation of a Zr-based glass [8].…”

“…In many cases the deformation of amorphous phases was observed to yield a crystallization reaction, for example upon cold-rolling of AI-Y-Fe and Al-Sm based amorphous ribbons [6], upon bending of different Al-based amorphous ribbons [7], warm-extrusion of gas-atomized amorphous powders [4,5] if the extrusion ratio exceeds a critical value or nanoindentation of a Zr-based glass [8]. A different approach towards bulk amorphous nanocomposites is the continued rolling and folding of crystalline, elemental multilayer arrays [9,101.…”