Pd--Si Binary Bulk Metallic Glass Prepared at Low Cooling Rate

We report that binary bulk metallic glasses can be made up to 6mm in diameter in a Pd--Si alloy system by air cooling at slow cooling rate (about 8K/s). The high stability of the undercooled liquid and the large glass-forming ability (GFA) of the binary alloy are contributed to the removing of heterogeneous impurities in the alloy melt by employing the fluxing technique. It has been found that decreasing cooling rate can increase the supercooled liquid region and thermal stability of the glassy alloy. After fluxing, a wider supercooled liquid region (ΔT=58K) and higher glass-forming ability have been obtained in a Pd₈₁Si₁₉ binary glassy alloy prepared by slow cooling rate.