Resistant Coatings for Metal Turbine Blades

Even with well equipped filtering techniques that are available today, sand ingestion reduce efficiency and life expectancy of gas turbine (GT) engines. A remedy for the problem is to coat related parts of the engine with a suitable material that can withstand the damage caused by the fast flying sand particles. From experiments conducted it is concluded that such materials should have high toughness, adherence to the part’s surface, moderate hardness and chemical stability at high temperature. All these capabilities could be obtained in Ti-B-N material system because of its unique capability of mixing various phases with contrasting properties. The method developed here is based on well established deposition process that can be used to form suitable nano-composite architecture possessing the required qualities. The feasibility of the work is supported by a number of publications by numerous research groups. In this work, a thick coating of nano-crystalline TiN phase imbedded in hexagonal boron nitride matrix will be synthesized with proper hardness and low stresses in a filtered vacuum arc system fitted with a magnetron sputtering gun. A gradient Ti-B-N bond-layer will provide the needed adhesion to avoid the delamination of the thick composite coating.