Method for determining of the coatings thermophysical properties formed by the microarc oxidation

Abstract

In this work are determined the thermophysical parameters (coefficient of thermal conductivity, thermal diffusivity and heat capacity) of a coating formed by the microarc oxidation (MAO) method on an aluminum alloy AK12D. A method for determining the thermal properties of the MAO layers was developed and verified. The technique is based on measuring the thermal conductivity of the layer by pulsed laser heating and calculating its heat capacity and density based on the data of layer-by-layer phase analysis taking into account the volume porosity. The method allows to calculate the thermophysical parameters whose values differ from the experimental no more than 2.2% in thermal conductivity and no more than 7.0% for heat capacity. In accordance with the proposed method, it was found that the MAO layer on AK12D alloy has a low thermal conductivity of ~ 1.57 W/(m·K) at 100 °C.