Fabrication of Ti(Al,O)-Al2O3 Powder Feedstock for Thermal Spraying and Evaluation of Composite Coating

Abstract

Ti(Al,O)-Al2O3 composite powders were produced by high energy mechanical milling of a mixture of Al and TiO2 powders followed by combustion reaction. The powders were then thermally sprayed on H13 steel substrates. Microstructural examination was conducted on the composite powders and thermally sprayed coatings using X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The performance of the coatings was evaluated in terms of microhardness and thermal fatigue. The thermally sprayed coatings showed fairly good performance in the preliminary thermal fatigue tests and did not display any wetting tendency to molten aluminum.