Formation and crystallization of bulk Pd₈₂Si₁₈ amorphous alloys

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ÎÄÕÂÒ³Â룺1056 - 1061

Key words£ºbulk amorphous alloys; Pd₈₂Si₁₈; glass forming ability; undercooling; critical cooling rate

Abstract: Bulk amorphous Pd₈₂Si₁₈ alloy with the largest diameter of 8mm was prepared by water quenching the molten alloy with flux medium in a quartz tube. The calculation result indicates that the bulk Pd₈₂Si₁₈amorphous alloys have a low critical cooling rate (R_c) of 4.589¤@K/s or less. The experimental results show that purifying melt may improve glass forming ability(GFA) of undercooled melt, while liquid phase separation (LPS) of undercooled melt will decrease its GFA. There are some differences in crystallization experiments between bulk metallic glass and amorphous ribbons of Pd₈2Si₁₈ alloys. These include the numbers of exothermic peak, glass transition temperature T_g, crystallization temperature T_x, region of undercooling liquid (¦¤T=T_x£­T_g) respectively. The links of cooling rates of melt and crystallization of Pd₈₂Si₁₈ amorphous alloys are explored.