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

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. Al85.35Y8Fe6V0.65 exhibits a crystallization-onset temperature (T-x) of 365 degrees C and a supercooled liquid region (Delta T-x) of 80 degrees C, the largest currently known for Al-rich metallic glasses. The rapidly quenched oxygenated alloys Al85Y8Fe6V0.65O0.35 and Al84.35Y8Fe6V0.65O1 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 Al85.35Y8Fe6V0.65 produces an unusual, non-uniform microstructure that suggests an autocatalytic nucleation mechanism.