本研究使用René 142鎳基超合金進行單方向凝固鑄造,以高溫氧化實驗的方式模擬航空渦輪葉片實際使用時的環境條件,分為直接使用單方向凝固鑄造材料(DS)以及單方向凝固鑄造試棒進行熱噴塗加工處理(DS+BC、DS+TBC)等試片,分別進行循環氧化及恆溫氧化實驗,並在恆溫氧化實驗的過程加入恢復熱處理之程序,分析其實驗結果,了解此材料之氧化行為,並確認材料的抗氧化性能在經過恢復熱處理前後之變化 ,以及在恢復處理前,不同的研磨深度對恢復熱處理後氧化性能及微觀組織的影響。在經過高溫循環氧化實驗之後,DS、DS+BC及DS+TBC三組試片的氧化行為有著明顯的差異。在高溫恆溫氧化實驗中,DS的試片被觀察到Al2O3、Ni2O等氧化層的形成與生長,而在DS+BC的試片中則觀察到添加塗層的材料在經過120個小時後底材仍被保護完整不受氧化影響。而恢復熱處理的程序對René 142的確是有用的,經過恢復熱處理之後不論是DS或DS+BC試片在γ′相的尺寸上都得到一定程度的恢復,在DS的試片中,研磨10μm再進行恢復熱處理的試片其微觀組織恢復得最好,而在DS+BC的試片中則是研磨3μm的試片在微觀組織的觀察上獲得較好的結果。
In this study, we use directionally solidified casting René 142 nickel-based superalloy as material. To simulate the environment condition of the turbine engine blades by the high temperature oxidation experimental. In the two test samples, one is the directionally solidified casting specimen (DS), another is the directionally solidified casting specimen with thermal barrier coating by thermal spray treatment (DS+BC, DS+TBC). To observe the oxidation behavior of René 142 and how the oxidation resistance and microstructure change after Isothermal oxidation and cyclic oxidation, samples will be analysis by SEM, EDS to the research. The difference of microstructure and oxidation resistance after rejuvenation heat treatment will be observed. And how the grinding depth before the Rejuvenation effect the oxidation resistance will be the point of the research After high temperature cyclic oxidation, the difference of DS, DS+BC and DS+TBC samples have clear trend. In the high temperature isothermal oxidation, Al2O3, Ni2O is formed to be the protection layer on René 142 DS sample. After 120 hours isothermal oxidation, the substrate have not be attack because of the protection of the coating in the DS+BC samples. The Rejuvenation heat treatment is effective in this research. The γ′ phase of DS and DS+BC samples are all have some restore after the Rejuvenation heat treatment. In the DS samples, the microstructure of the grinding depth 10μm was better and the grinding depth 3μm was better in the DS+BC samples.