Ti-Al-Zr-B-Y Amorphous Alloy Powders Prepared by Mechanical Alloying

Abstract

Mechanical alloying (MA) is used to prepare amorphous alloy powders. The experiments were performed by a high energy ball milling device using stainless steel vessels and balls under argon atmosphere at a rotation rate of 450 r/min. B and Y were used as the minor additions to prepare new quaternary or complex amorphous alloy powders. Ti50Al(47-x-y)Zr3BxYy(x=0, 0.6, y=0, 0.2) amorphous alloy powders were successively obtained. The milled amorphous alloy powders were characterized by XRD, SEM and DSC. Ti50Al47Zr3amorphous alloy powders were obtained after milled 50h. The milling time needed to obtain complete amorphous alloy for Ti50Al46.4Zr3B0.6, Ti50Al46.8Zr3Y0.2and Ti50Al46.2Zr3B0.6Y0.2are 40h, 35h and 30h, respectively. Minor additions of B and Y decreases the milling time for preparing amorphous alloy. SEM shows that B and Y can refine the grain of the amorphous alloy powders. DSC shows that minor substitution of 0.6at.%B or 0.2at.%Y can increase the glass forming ability (GFA) for the TiAl based alloys.