Porous nanostructured ZrO2 coatings prepared by plasma spraying

Porous nanostructured ZrO2 coatings were prepared on the surface of TC4 titanium alloy by plasma spraying. The porosity of the coatings was improved by adding MDPE and PEEK as pore-forming agents in the ZrO2 powder. The results indicate that the addition of pore-forming agents significantly increased the porosity of the ZrO2 coatings, and the porosity of the ZrO2 coatings increased with increasing the content of the pore-forming agents. PEEK pore-forming agent was superior to MDPE concerning the pore-forming ability in the present preparation condition. The porosity of the ZrO2 coatings was further increased by subsequent heat treatment. The porosity of ZrO2–15% PEEK coating after heat treatment reached 20.6%. The microhardness of the porous nanostructured ZrO2 coatings were about HV0.11000, which decreased little with the increase of the porosity of the coatings.