共鳴超音波スぺクトロスコピーによる耐熱コーティングのヤング率異方性測定

摘要

耐熱コーティングMCrAlY（MはCoやNi）は耐食?rn耐酸化を目的としてガスタービンプラントで使用されrnている．部位によっては耐熱コーティングのみで使用rnされることもあるが，遮熱コーティング(TBC）と超合rn金基材の中間層としてボンドコートを兼ねて用いられrnることが多い．%Heat resistant coatings have been used in gas turbine blades and combustors. The resonance ultrasound spectroscopy method by the needle-transducer tripod was expanded to high temperature measurement in order to clarify the all directional Young's moduli of heat resistant coatings. The resonance spectrum was measured up to 1 073 K by the equipment with induction heating and remote sensing by laser-Doppler interferometry, which was originally developed. Following results were obtained from the measurement of atmospheric plasma sprayed CoNiCrAlY coatings : The in-plane Young's modulus increased with a decrease in the size of spraying powder. On the contrary, the out-plane modulus decreased. It meant that the anisotropy of the elastic modulus became remarkable with a decrease in the size of spraying powder. The enhancement of Young's modulus by thermal treatment was much significant in out-plane direction than in-plane direction. Consequently, the anisotropy of the elastic modulus became insignificant and negligible in the case of the thermally treated coating with large spraying powder.