The thermal stability and activation energy of crystallization Of (Cu61.8Zr38.2)1-xAlx bulk metallic glasses

The present paper reports on the thermal stability and activation energy of crystallization of bulk metallic glasses (BMGs) (CU61.8Zr38.2)(1-x)Al-x. The (CU61.8Zr38.2)(1-x)Al-x composition series, prepared by copper mould suction casting into bars with a diameter of 3 mm, form BMGs with an e/a range of 1.24-1.3. These BMGs manifest increased thermal stability with increased e/a ratios. The activation energies (Delta E) of crystallization as derived from thermal analysis at different heating rates follow a similar tendency to that of the thermal stability, indicating stronger short-range ordering with increasing e/a ratios. The optimum BMG CU58.1Zr35.9Al6 exhibits the highest thermal stability and the largest Delta E. (c) 2007 Elsevier B.V. All rights reserved.