Effects of the Time and Temperature on the Oxide Scale Formed on the Cobalt Alloys

Abstract

The cobalt base PTA (Plasma Transferred Arc) clad layers were investigated under different temperature and time of oxidation. The microstructure of the clads after oxidation demonstrated degradation process which led to the decomposition of the dendrite boundaries. Chemical compositions of the formed scales were depending on the oxidation temperature, chemical composition of the alloy, especially small addition of the silicon, and time of the exposition.