Rapid solidification of Al-Cu-Ag ternary alloy under the free fall condition  

作　　者：DAI FuPing WEI BingBo 

机构地区：[1]Department of Applied Physics,Northwestern Polytechnical University,Xi’an 710072,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2009年第6期848-855,共8页中国科学：物理学、力学、天文学（英文版）

基　　金：Supported by the National Natural Science Foundation of China (Grant Nos.50121101 and 50395105)

摘　　要：The rapid solidification of Al-30%Cu-18%Ag ternary alloy is investigated by using the free fall method. Its solidified microstructure is composed of θ(Al2Cu), α(Al) and ξ(Ag2Al) phases. The liquidus temperature and solidus temperature are determined as 778 and 827 K, respectively. The alloy melt undercooled amounts up to ΔTMax=171 K (0.20TL). Its microstructural evolution is investigated based on the theoretical analysis of undercooling behavior and nucleation mechanics. It is found that the undercooling increases with the decrease of the diameter of the alloy droplet. When ΔT<78 K, the primary θ (Al2Cu) phase of the alloy grows into coarse dendrite. When 78 K≤ΔT≤171 K, its refined θ (Al2Cu) phase grows alternatively with α(Al) phase. Once ΔT≥171 K, its microstructure is characterized by the anomalous (θ+α+ξ) ternary eutectic.The rapid solidification of Al-30%Cu-18%Ag ternary alloy is investigated by using the free fall method. Its solidified microstructure is composed of θ(Al2Cu), α(Al) and ξ(Ag2Al) phases. The liquidus temperature and solidus temperature are determined as 778 and 827 K, respectively. The alloy melt undercooled amounts up to ΔT Max=171 K (0.20T L). Its microstructural evolution is investigated based on the theoretical analysis of undercooling behavior and nucleation mechanics. It is found that the undercooling increases with the decrease of the diameter of the alloy droplet. When ΔT<78 K, the primary θ(Al2Cu) phase of the alloy grows into coarse dendrite. When 78 K?ΔT?171 K, its refined θ(Al2Cu) phase grows alternatively with α(Al) phase. Once ΔT?171 K, its microstructure is characterized by the anomalous (θ+α+ξ) ternary eutectic.

关 键 词：Al-Cu-Ag free FALL NUCLEATION TERNARY EUTECTIC rapid solidification high UNDERCOOLING 

分 类 号：TG131[一般工业技术—材料科学与工程]