Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (34권2호 161-168)

A study on the high temperature properties of CoNiCrAlY coating fabricated by HVOF and LPPS process

LPPS용사법과 HVOF 용사법으로 제조된 CoNiCrAlY 코팅의 고온물성에 관한 연구

강현욱;권현옥;송요승;

한국항공대학교 항공재료공학과;

Abstract

A Thermal Barrier Coating (TBC) can play an important role in protecting parts from harmful environments at high temperatures such as oxidation, corrosion, and wear in order to improve the efficiency of aircraft engines by lowering the surface temperature of the turbine blade. The TBC can increase the life span of the product and improve the operating properties. Therefore, in this study the mechanical and thermal properties of the TBC such as oxidation, fatigue and shock at high temperatures were evaluated. A samples of a bond coat (CoNiCrAlY) produced by the High Velocity Oxygen Fuel (HVOF) and Low Pressure Plasma Spray (LPPS) method were used. The thickness of the HVOF coating layer was approximately $450mu extrm{m}$ to 500$mu extrm{m}$ and the hardness number of the coating layer was between 350Hv and 400Hv. The thickness of the LPPS coating was about 350$mu extrm{m}$ to 400$mu extrm{m}$ and the hardness number of the coating was about 370Hv to 420Hv. The X-ray diffraction analysis showed that CoNiCrAlY coating layer of the HVOF and LPPS was composed of the $eta$and ${gamma}$phase. After the high temperature oxidation test, the oxide scale with about l0$mu extrm{m}$ to 20$mu extrm{m}$ thickness appeared at the coating surface on the Al-depleted zone was observed under the oxide scale layer.

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