Molina Jordá, José Miguel, Rodríguez Guerrero, Alejandro, Louis, Enrique, Rodríguez Reinoso, Francisco, Narciso, Javier Porosity Effect on Thermal Properties of Al-12 wt % Si/Graphite Composites Molina J-M, Rodríguez-Guerrero A, Louis E, Rodríguez-Reinoso F, Narciso J. Porosity Effect on Thermal Properties of Al-12 wt % Si/Graphite Composites. Materials. 2017; 10(2):177. doi:10.3390/ma10020177 URI: http://hdl.handle.net/10045/63348 DOI: 10.3390/ma10020177 ISSN: 1996-1944 Abstract: The effect of porosity on the thermal conductivity and the coefficient of thermal expansion of composites obtained by infiltration of Al-12 wt % Si alloy into graphite particulate preforms has been determined. Highly irregular graphite particles were used to fabricate the preforms. The thermal conductivity of these composites gradually increases with the applied infiltration pressure given the inherent reduction in porosity. A simple application of the Hasselman-Johnson model in a two-step procedure (that accounts for the presence of both graphite particles and voids randomly dispersed in a metallic matrix) offers a good estimation of the experimental results. As concerns the coefficient of thermal expansion, the results show a slight increase with saturation being approximately in the range 14.6–15.2 × 10−6 K−1 for a saturation varying from 86% up to 100%. Results lie within the standard Hashin-Strikman bounds. Keywords:Graphite particles, Porosity, Gas pressure infiltration, Thermal conductivity, Coefficient of thermal expansion MDPI info:eu-repo/semantics/article