Processing Zr52.5Cu17.9Ni14.6Al10Ti5 metallic glass containing high levels of oxygen by microalloying with erbium

Zr52.5Cu17.9Ni14.6Al10Ti5 was doped with oxygen and erbium to determine the effect of impurity oxygen and microalloying on the stability of the liquid during processing from the melt. It was established that oxygen concentrations of 5000–14,000 ppm (atomic herein) destabilized the alloy significantly, consistent with data trends seen in the literature. The oxygen containing materials crystallized into tetragonal and cubic intermetallics during processing. The highest levels of oxygen facilitated complete transformation to the cubic structure. The addition of 0–1 at.% rare-earth Er to the impure materials stabilized the liquid by the formation of anticatalyst (Er, Al)2O3 dispersions, allowing the production of glassy matrix composites in the form of 6.4 mm diameter × 70 mm rods with oxygen contents up to 16,000 ppm. Compression testing of the Er-doped samples showed that their rupture strengths varied little with Er/O content.