Fe-based bulk metallic glasses with Y addition

This paper aims to study the role of residual vacuum during sample preparation and of quenching rate on glass formation in Fe50-xCr15Mo14YxC15B6 (x = 0, 2) alloys. The equilibrium phase mixture has been clarified for both alloys, combining X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. The beneficial effects of minor addition of Y on the glass formation are evidenced. A high residual vacuum during sample preparation promotes glass formation. Glass transition temperature for amorphous sample containing 2 at.% Y is 881 K and the onset crystallization temperature is 904 K. The melting behavior for both as-cast alloys were measured with high temperature differential scanning calorimeter (HTDSC). Melting starts at 1384 K, ends at 1506 and 1470 K as liquidus temperatures for Fe50Cr15Mo14C15B6 and Fe48Cr15Mo14Y2C15B6 alloys, respectively. The addition of Y leads to a melting behavior of as-cast sample close to eutectic, which enhances glass formation. (C) 2006 Elsevier B.V. All rights reserved.