Formation and crystallization of bulk Pd82Si18 amorphous alloys
(State Key Lab of Plastic forming Simulation and Die & Mould Technology, Huazhong University of Science & Technology,
Wuhan 430074,China)
Wuhan 430074,China)
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 (Rc) of 4.589K/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 Tg, crystallization temperature Tx, region of undercooling liquid (ΔT=Tx－Tg) respectively. The links of cooling rates of melt and crystallization of Pd82Si18 amorphous alloys are explored.
Key words: bulk amorphous alloys; Pd82Si18; glass forming ability; undercooling; critical cooling rate