An Al-rich metallic glass with a large supercooled liquid region

Abstract

The addition of small amounts (microalloying) of Ti was previously shown to improve glass formation and stability in rapidly quenched Al–Y–Fe alloys. Here, microalloying with V is demonstrated to have an even more dramatic effect on glass stability. Al_85.35Y₈Fe₆V_0.65 exhibits a crystallization-onset temperature (T_x ) of 365°C and a supercooled liquid region (ΔT_x ) of 80°C, the largest currently known for Al-rich metallic glasses. The rapidly quenched oxygenated alloys Al₈₅Y₈Fe₆V_0.65O_0.35 and Al_84.35Y₈Fe₆V_0.65O₁ are also glasses, establishing that the glasses with V have a higher tolerance to oxygen contamination than the alloys prepared with Ti. The partial devitrification of Al_85.35Y₈Fe₆V_0.65 produces an unusual, non-uniform microstructure that suggests an autocatalytic nucleation mechanism.

Acknowledgment

This work was funded by the United States Air Force Office of Scientific Research Grant No. 9550-05-1-0110.