Melting Temperature and Wetting Angle of AlN/Dy₂O₃ and AlN/Yb₂O₃ Mixtures on SiC Substrates

Abstract

This work aims to evaluate the melting temperature and wetting behavior of AlN/Re₂O₃ (Re = Dy, Yb) mixtures when in contact with SiC substrates at high temperatures, in order to define whether these compounds can be further used to induce a more effective liquid phase sintering of SiC-based products. The prepared samples were placed on SiC plates and thermally treated up to 1900 °C under argon. The melting point and spreading evolution of different compositions of AlN/Re₂O₃ on SiC were determined by analyzing images captured as a function of the heating temperature. The contact angle and melting point were measured using the ImageJ software and according to DIN 51730, respectively. Based on the obtained wetting curves, all evaluated conditions resulted in the decrease of the contact angle values with temperature. The mixtures presenting improved wetting (θ ~ 1° and 3°) on SiC plates were the ones above the selected eutectic point.

Keywords:
SiC; AlN; rare earth oxides; wettability; contact angle