Kinetics of heat flow in ceramic particle - metal matrix system
Mirosław Cholewa Politechnika Śląska, Wydział Mechaniczny Technologiczny, Instytut Materiałów Inżynierskich i Biomedycznych, Zakład Odlewnictwa ul. Towarowa 7, 44-100 Gliwice
Annals 4 No. 12, 2004 pages 444-450
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abstract The main aim of composite solidification process control is the optimization of its technological and exploitation properties. Knowledge about correlation between matrix and reinforcement allows to form the matrix structure. In this work the analysis of typical region of solidifying composite containing ceramic particle (Fig. 1), both having diversified initial temperatures was shown. The transition zone was neglected and full wetting was assumed. The object of this work is one of the two specific associations, namely the ceramic particle with poor heat conductivity and metal matrix with high heat conductivity. As assumed the considered region was placed on heat flow direction which center was located in casting space - outside the considered region. One-dimensional heat flow in flat rectangular particle and matrix region to surroundings was studied. The surroundings was assumed to have properties of solidified composite. The studies results are shown on diagrams in Figures 2 and 3 created on base of temperature changes determined through computer simulation. In direct neighbourhood of the reinforcement the first derivatives of temperature over time and heat give - up direction were studied. It was found that depending on initial temperatures the velocity of heat give - up and temperature gradients can change its values and sign in initial stage of solidification and hence influence the structural parameters, which examples are shown in Table 1. Key words: metal matrix composite, solidification, crystallization