Thermal stability of laminated Ru-Al/Ru-Si-Zr coatings on Inconel 617

• Main Authors: Lo, Hsien-Hao, 羅憲豪
• Other Authors: Chen, Yung–I
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/a9bhn8

碩士 === 國立臺灣海洋大學 === 材料工程研究所 === 107 === A previous study has evaluated the thermal stability of laminated Ru–Al/Ru–Al–Zr coatings on Inconel 617 substrates at 800°C in ambient air. A dense Al2O3 scale was formed on the top of the Ru–Al coatings after annealing and the oxide layers restricted the inward diffusion of oxygen. The remaining Ru–Al coatings could not prevent the substrate elements from outward diffusion. The Ru–Al–Zr underlayers maintained a multilayered structure with cyclic gradient concentration after annealing for 30 min. However, they transformed into a polycrystalline structure with grain sizes of tens of nm after a 4-h annealing accompanied with the interdiffusion of metallic elements of the coatings and substrates. In this study, multilayered Ru–Si–Zr coatings were fabricated and their thermal stability at 800°C in air was examined by using transmission electron microscopy and Auger electron spectroscopy. The results indicated that the interdiffusion between the Ru–Si–Zr coatings and Inconel 617 substrates was retarded by maintaining the multilayered structure constructed with alternative stacks of the Zr-oxide and a mixture of Si-oxide and Ru dominant solid solution sublayers.