Effect of porosity on the thermalconductivity of copper processed by powder metallurgy
Langue
en
Article de revue
Ce document a été publié dans
Journal of Physics and Chemistry of Solids. 2012, vol. 73, n° 3, p. 499-504
Elsevier
Résumé en anglais
Powder metallurgy is a preferred method of processing copper-carbon composites due to the non-wetting nature of these materials. Porosities are inherently introduced in these material systems, and adversely affect the ...Lire la suite >
Powder metallurgy is a preferred method of processing copper-carbon composites due to the non-wetting nature of these materials. Porosities are inherently introduced in these material systems, and adversely affect the thermal conductivity of the composite material, among other factors including interfaces and reinforcement distribution. In this work, we focus on the matrix material of pure copper and systematically analyzed the effect of volume fraction of porosities on the thermal conductivity. Spherical and dendritic copper powder materials were processed and it was found that the surface chemistry and morphology of particles affected the thermal conductivity apart from the porosity values. In order to study the effect of porosities alone, dentritic powder was used in the study. The thermal conductivity vs. porosity behavior showed three distinct domains. In all the domains the thermal conductivity decreases as volume fraction of porosities increases; however, in domain II, the decrease was much steeper than the other two. We are able to explain the variation based on the presence of interconnected and open pores in domain III to closed pores in domain I, and the transition occurring in domain II. None of the existing models capture the overall behavior. However, if we specifically account for the variation of number of grain boundaries with sintering, then the modified EMT model can match the experimental data.< Réduire
Mots clés en anglais
Metals
Microporous materials
Thermal conductivity
Origine
Importé de halUnités de recherche