Glass forming ability of the Zr50Cu40Al10 alloy with two oxygen levels

• Published in: Journal of non-crystalline solids Vol. 496; pp. 42 - 47
• Main Authors: Pajor, Krzysztof, Kozieł, Tomasz, Cios, Grzegorz, Błyskun, Piotr, Bała, Piotr, Zielińska-Lipiec, Anna
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.09.2018
• Subjects: Bulk metallic glasses; Critical diameter; Glass forming ability; Oxygen content; Thermal stability; Zirconium; Zirconium; Oxygen content; Critical diameter; Bulk metallic glasses; Thermal stability; Glass forming ability
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2018.05.034

The effect of oxygen content on the glass forming ability of the Zr50Cu40Al10 alloy is presented. Two different oxygen levels, 194 ± 26 wt. ppm and 918 ± 72 wt. ppm, in the arc melted and suction cast alloys were obtained using Zr metal of different forms and nominal oxygen contents. Critical diameters for glass formation were determined by microstructural observations of cast conical and rod-shaped samples. Their structures were further investigated by X-ray diffraction. The critical diameter of the alloy with the lower oxygen content was 8 mm, while for the higher oxygen content it was below 3 mm. For the latter, the τ3 (Zr51Cu28Al21) crystalline inclusions were observed in the central part of the 3 mm diameter sample. The fully amorphous samples exhibited a large supercooled liquid range and a high reduced glass transition temperature. •Oxygen contamination significantly reduced glass forming ability of Zr-based bulk metallic glasses.•Small crystalline inclusions embedded in the amorphous matrix were detected by electron microscopy.•The use of the conical method allows to quickly and easily predict the critical diameter for glass formation.•The best indicator of glass forming ability based on thermal analysis is the γm parameter.