The influence of SiO 2 nanoparticles addition into electrolyte on the thermal conductivity of oxide layer formed on eutectic aluminum-silicon alloy by PEO

Abstract

Oxide layers formed by plasma electrolytic oxidation with SiO 2 nanoparticles addition into electrolyte on eutectic aluminum-silicon alloy were investigated by scanning electronic microscopy (SEM), energy dispersive X-ray microanalysis (EDXMA) and X-ray diffraction (XRD) analysis. The thermal conductivity of oxide layers was measured by constant heat flow method. Obtained values of the thermal conductivity of oxide layers are significantly smaller than the values of oxide layer components as bulk materials. Decreasing of thermal conductivity of oxide layer in ratio of two is observed if SiO 2 nanoparticles are added into electrolyte. It is shown that the sedimentation of nanoparticles into oxide layer and decreasing of crystalline sizes are the reasons of decreasing of thermal conductivity.