The critical cooling rate and microstructure evolution of Zr41.2Ti13.8Cu12.5Ni10Be22.5 composites by Bridgman solidification

The critical cooling rate and microstructure evolution were experimentally studied at cooling rates between 0.85 and 15.34 K/s by a Bridgman technique in Vit-1 (Zr41.2Ti13.8Cu12.5Ni10Be22.5). Our results show that the sample solidified at the rate above 10.03 K/s was fully amorphous whereas the samples solidified between 1.70 and 10.03 K/s were partially amorphous with crystalline phases, and samples solidified below 1.70 K/s were essentially crystalline. As the cooling rate decreased from 15.34 K/s to 1.82 K/s, the values of Tg and Tx were around 628 K and 702 K, respectively, but the heat of crystallization (ΔHx) decreased with decreasing cooling rate.