Microstructure and Mechanical Properties of TiO₂ Coatings Prepared by Plasma Spray Technique

Plasma spray technique is used to produce coatings with excellent hardness, wear resistance and strong adhesion. TiO2 coatings were prepared by plasma spraying at low plasma power.TiO2 powder with anatase phase structure was used to prepare the coatings. The effect of plasma spraying parameters on the microstructure and mechanical properties of the coatings were investigated. The microstructure of the coatings showed that the coatings were formed by fully and partially melted particles. The coatings dominant phase is rutile and only a few coatings contained traces of anatase phase. The hardness and adhesion strength of the coatings were tested using Vickers microhardness and pull-off adhesion tester. The adhesion strength obtained was between 10-20 MPa and the microhardness result is between 300 - 800 Hv. The spraying parameters such as input power, spraying distance and plasma gas ratio influenced the properties of the produced coatings.