Suspension plasma sprayed composite coating using amorphous powder feedstock

Al2O3–ZrO2 composite coatings were deposited by the suspension plasma spray process using molecularly mixed amorphous powders. X-ray diffraction (XRD) analysis shows that the as-sprayed coating is composed of α-Al2O3 and tetragonal ZrO2 phases with grain sizes of 26 nm and 18 nm, respectively. The as-sprayed coating has 93% density with a hardness of 9.9 GPa. Heat treatment of the as-sprayed coating reveals that the Al2O3 and ZrO2 phases are homogeneously distributed in the composite coating.