The onset of solutal convection during the directional solidification of Bridgman type of liquid Al-3.5 wt%Li is studied. Based on the analysis of a liquid-inhomogeneous-porous-double-layer system, a bimodal feature of neutral stability curve is found. The pulling rate is ascertained as the governing parameter for the mode transition, i.e., it determines whether the microstructure in the mushy layer is related to convection after the system destabilizes.
Supported by the Fundamental Research Funds for the Central Universities under Grant No 2014JBM098, the National Natural Science Foundation of China under Grant Nos 11502015 and 11532015, and the Open Research Fund Program of Jiangsu Key Laboratory of Engineering Mechanics, Southeast University, under Grant No LEM16A05.
[Zhao, Si-Cheng] Beijing Jiaotong Univ, Sch Civil Engn, Dept Mech, Beijing 100044, Peoples R China; [Zhao, Si-Cheng] Southeast Univ, Jiangsu Key Lab Engn Mech, Nanjing 210096, Jiangsu, Peoples R China; [Liu, Qiu-Sheng] Chinese Acad Sci, Inst Mech, Key Lab Micrograv, Beijing 100080, Peoples R China; [Nguyen-Thi, Henri; Billia, Bernard] Univ Aix Marseille, UMR CNRS 6137, IM2NP, F-13397 Marseille 20, France