Study on the electrical and mechanical properties of plasma sprayed titanium oxide coatings

Abstract

Titanium oxide is a material that changes its physical properties due to the formation of oxygen vacancies in the crystal lattice. This phenomenon is especially observed in the plasma spray process. The lattice defects in the consolidated coating material strongly determine its mechanical (tribological) and electrical properties. The crystalline phases that are formed in the coating (anatase, rutile) have also to be taken into account. In his study the electrical properties of plasma sprayed titanium oxides will be investigated. The influence of plasma spray parameters will be studied by means of DOE, two different plasma spray systems will be used: A standard DC single cathode torch (F6, GTV) and a three cathode torch (type MAGNUM, GTV). The coatings will be characterized using standard analytical tools (XRD, SEM, LM, microhardness, electrical conductivity etc.) A potential industrial application of titanium oxide coating is its use as an electrical conductive material applied on glass ceramic substrates. Some basic parameter studies considering torch kinematic will be performed to improve mechanical stability of such coatings on the glass ceramic substrate. Another interesting approach is the mixing of titanium oxide with a Ni-CrAIY powder to form a composite powder. The idea is to increase the electrical conductivity, but keep the thermomechanical properties of the oxide material.