Phase separation and rapid solidification of liquid Cu_(60)Fe_(30)Co_(10) ternary peritectic alloy
Phase separation and rapid solidification of liquid Cu_(60)Fe_(30)Co_(10) ternary peritectic alloy作者机构:Department of Applied Physics Northwestern Polytechnical University Xi’an China
出 版 物:《Science China(Physics,Mechanics & Astronomy)》 (中国科学:物理学、力学、天文学(英文版))
年 卷 期:2007年第50卷第4期
页 面:509-518页
核心收录:
学科分类:07[理学] 070205[理学-凝聚态物理] 0702[理学-物理学]
基 金:the National Natural Science Foundation of China (Grant Nos. 50121101 and 50395105) the Scientific and Technological Creative Foundation of Youth in Northwestern Polytechnical University of China (Grant No. W016223)
主 题:ternary peritectic alloy metastable immiscibility rapid solidification reduced gravity liquid phase separation
摘 要:The metastable liquid phase separation and rapid solidification of Cu60Fe30Co10 ternary peritectic alloy were investigated by using the drop tube technique and the differential scanning calorimetry method. It was found that the critical temperature of metastable liquid phase separation in this alloy is 1623.5 K, and the two sepa- rated liquid phases solidify as Cu(Fe,Co) and Fe(Cu,Co) solid solutions, respec- tively. The undercooling and cooling rate of droplets processed in the drop tube increase with the decrease of their diameters. During the drop tube processing, the structural morphologies of undercooled droplets are strongly dependent on the cooling rate. With the increase of the cooling rate, Fe(Cu,Co) spheres are refined greatly and become uniformly dispersed in the Cu-rich matrix. The calculations of Marangoni migration velocity (VM) and Stokes motion velocity (VS) of Fe(Cu,Co) droplets indicated that Marangoni migration contributes more to the coarsening and congregation of the minor phase during free fall. At the same undercooling, the VM/VS ratio increases drastically as Fe(Cu,Co) droplet size decreases. On the other hand, a larger undercooling tends to increase the VM/VS value for Fe(Cu,Co) drop- lets with the same size.