Effect of Al Addition on Glass Forming Ability and Glass Stability of Ca-Mg-Zn-Cu Based Bulk Metallic Glasses

Abstract

The effect of Al addition on glass forming ability (GFA) and stability of the glassy phase against crystallization was studied for Ca-Mg-Zn, Ca-Mg-Cu, and Ca-Mg-Zn-Cu alloys. The glassy alloys were produced by copper mold casting as wedge-shaped samples with thicknesses varying from 0.5 to 10 mm. Thermal properties, such as glass transition, crystallization and melting temperatures, as well as heats of crystallization and melting, were determined for the produced glasses. Partial substitution of Zn or Cu with Al was found to improve the glass stability (GS) against the general tendency to reduce the GFA.

Crystallization kinetics of GdYScAlCo high-entropy bulk metallic glass

“…Compared to other metallic glasses: La55Al25Ni20 (m = 42, F1 = 0.455), La55Al25Ni10Cu10 (m = 35, F1 = 0.540) [11], the alloy GdYScAlCo shows rather high values in frazilite and the F1 parameter, which indicates its good glass forming ability.…”

“…The parameter F1, introduced by Senkov [11], is an indicator of glass-forming ability, which establishes a correlation between the fragility parameter and the critical cooling rate at which the amorphous state is formed. The value F1 = 0 corresponds to an extremely fragile liquid, and F1 ~ 0.8 -extremely strong liquid.…”

Archives of Foundry Engineering

“…3, Fig. 4) [4]; [5]; [22] Selected samples were studied with corrosion tests. The potentiostatic studies have shown some characteristic features that prove the formation of the passive layer (Fig.…”

“…The master alloy with a nominal composition of Ca 50 Mg 20 Zn 12 Cu 18 in atomic percent was used. Alloy ingot was produced by induction melting mixtures of pure elements (Ca 99.5%, Mg 99.8%, Zn 99.995%, Cu 99.95%) and Mg69Ca31 alloy under an argon atmosphere [4]; [5]; [21]. Then the pieces of the ingot (W1 sample) were remelted several times to ensure chemical homogeneity [3]; [5].…”

“…In his work, Zberg carried out in vivo studies using MgZnCa metallic glasses, which showed biocompatibility and lower hydrogen evolution [2]; [3]. Due to the combination of biocompatibility and mechanical properties, metallic glasses seem to be a good way to develop implantology [4]; [5].…”