Analysis of the influence of ceramic particles on the solidification process of metal matrix composites

The paper presents an analysis of influence of the ceramic particles on solidification and crystallization of metal matrix composites (MMCs). The analysis is performed on the basis of the kinetics of the solidification heat liberation and of the theory of nucleation and growth of the solid phase nuclei in the matrix. The heat of the solidification is determined by differential thermal analysis and the heat source function beta is calculated. Theoretical considerations have been verified by the results of the authors' own investigations performed on AlSi7Mg4 alloy composites reinforced with SiC particles of various sizes (15, 40 and 75 mu m) present in various amounts (10, 15, and 20 strength). The possibility of determining the solidification kinetics of individual phases of the composite matrix and the qualitative assessment of the nucleation rate of the primary solid phase in the matrix, by means of the ATD method and the beta function, has been proved. (C) 2000 Elsevier Science S.A. All rights reserved.