Heat treatment of the CrTaO4 forming model alloy Cr-20at.%Ta is investigated to find a reliable homogenization process for further high temperature oxidation experiments. Heat treatment of the model alloy at 1200°C and 1300°C shows significant microstructural differences within a single sample. Fine, parallel plates originating from the eutectoid phase transormation from the C14 into the A2 and C15 phase can be found, as well as A2 precipitates within the C15 phase.