Grain Nucleation Parameters for Aluminum Alloys: Experimental Determination and Model Validation

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 40; no. 3; pp. 646 - 653
• Main Authors: Ahmadein, M., Pustal, B., Berger, R., Subašić, E., Bührig-Polaczek, A.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.03.2009; Springer; Springer Nature B.V
• Subjects: Accuracy; Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Exact sciences and technology; Experiments; Grain size; Materials Science; Mechanical properties; Metallic Materials; Metals. Metallurgy; Nanotechnology; Simulation; Solidification; Solids; Standard deviation; Structural Materials; Surfaces and Interfaces; Temperature distribution; Thin Films; Nucleation Parameter; Cool Rate; Cast Sample; High Cool Rate; Nucleation Model; Modeling; Germination
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-008-9738-4

A statistical grain nucleation model was implemented as a part of a multiphase flow and solidification simulation code for metallic alloys. Three characteristic parameters control the solution accuracy of the nucleation model: the total grain density, the mean undercooling, and the standard deviation of the undercooling. These parameters were obtained experimentally for grain-refined (GR) A356, GR AlCu4, and unrefined (UR) AlCu4 aluminum alloys. An apparatus was constructed and equipped with a cooling system to provide different cooling rates throughout the cast sample. The local grain density related to each cooling rate and undercooling was determined. The model parameters were obtained via statistical tools and were used to perform a simulation for the solidification of the cast sample. Calculated results were compared to experimental results, and the model exhibited good agreement with the experiments.