Lightweight Ti-Zr-Be-Al bulk metallic glasses with improved glass-forming ability and compressive plasticity

A series of lightweight Ti-Zr-Be-Al bulk metallic glasses (BMGs) have been developed through the addition of Al to Ti-Zr-Be ternary glassy alloy. By replacing Be with Al, the critical size of the glassy rod has been increased from 5 mm for Ti41Zr25Be34 alloy to 7 mm for Ti(41)Zr(25)Be(29)A(15) alloy, while the yield strength of Ti41Zr25Be34-xAlx (x = 2-10) has been greatly enhanced, resulting in a significant increase of the specific strength which is defined as yield strength/density. Among these newly developed Ti-Zr-Be-Al BMGs, Ti41Zr25Be26Al8 glassy alloy exhibits a high specific strength of 4.33 x 10(5) Nm/kg and a very large compressive plastic strain of 47.0%, which are much larger than those (3.69 x 10(5) Nm/kg and 2.9%, respectively) for Ti41Zr25Be34 glassy alloy. The present results show that Al is an effective alloying element for improving the glass-forming ability (GFA) and mechanical properties of Ti-Zr-Be glassy alloy. (C) 2012 Elsevier B.V. All rights reserved.