Primary Dendrite Trunk Diameter in Al-7wt% Si Alloy Directionally Solidified Aboard the International Space Station

Joint 5th International Conference on Advances in Solidification Processes;5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining

土木建筑工程;计算机科学

Upadhyay, S.R.^1 ; Tewari, S.N.^2 ; Ghodes, M.^3 ; Grugel, R.N.^4 ; Poirier, D.R.^5 ; Lauer, M.^6

Engineer-Metallurgical, RioTinto Kennecott Copper, 11600 W. 2100 South, Magna

UT, United States^1

Chemical and Biomedical Engineering Department, Cleveland State Uniersity, Cleveland

OH

44115, United States^2

Assistant Prof., Middle East Technical University, Northern Cyprus Campus, Güzelyurt, Mersin

10, Turkey^3

Scientist, NASA-Marshall Space Flight Center, Huntsville

AL

35812, United States^4

Department of Materials Science and Engineering, University of Arizona, Tucson

AZ

85721, United States^5

Engineer, ME Elecmetal Inc., Duluth

MN

55808, United States^6

关键词: Collaborative research projects;    Directionally solidified;    European Space Agency;    International Space stations;    Magnetically controlled convection;    Microstructure formation;    National aeronautics and space agencies;    Thermosolutal convection;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/529/1/012022/pdf
DOI  :  10.1088/1757-899X/529/1/012022

来源: IOP

【 摘 要 】

Under a NASA (National Aeronautics and Space Agency)-ESA (European Space Agency) collaborative research project, MICAST (Microstructure formation in casting of technical alloys under a diffusive and magnetically controlled convection conditions), three Al-7wt% Si samples (MICAST-6, MICAST-7 and MICAST2-12) were directionally solidified at growth speeds varying from 10 to 50 μm s-1 aboard the International Space Station to determine the effect of mitigating convection on the primary dendrite array. The observed primary dendrite trunk diameters during steady-state growth of MICAST samples show a good agreement with predictions from a coarsening based model developed by the authors. The trunk diameters in the terrestrial-grown equivalent samples were larger than those predicted from the model. This suggest that thermosolutal convection increases the trunk diameter of primary dendrites, perhaps by increasing their tip radius due to compositional changes.