|Abstract: ||此研究應用電漿熔射法製備四組不同噴覆條件之絕熱塗層,即噴覆過程中有無氣冷,以及有無介層之存在;塗層之檢定包括相分析、顯微結構觀察、微硬度檢測、表面探傷劑檢測、四點彎曲試驗與同步(in situ)聲波放射試驗。實驗結果顯示當噴覆時使用氣冷,所得之塗層有良好之完整性;若無氣冷,則在陶瓷層內,會有一因熱應力過大產生之裂縫帶。當基材噴覆上一層絕熱塗層後,因為塗層與基材結合而成一種強化複合層式的材料,其彈性模數值比基材為高,降伏應力亦增加;同步聲波放射試驗顯示:當塗層製備時,有無氣冷或有無介層存在,在聲波放射反應數及事件能量上有明顯之差異;同時表面探傷之裂縫觀察可以發現在樣品表面有平行於施力之裂縫出現。|
In the current study, thermal barrier coatings (TBC) were plasma sprayed under different conditions, i.e., with or without air cooling during spraying, and with or without bond coat. The as-sprayed coatings were analyzed by X-ray diffraction, SEM, microhardness, dye penetration test, and four point bending with in situ acoustic emission (AE). The results showed that TBC containing bond coat and sprayed with air cooling exhibited best properties. The AE responses for these coatings exhibited not only lower in event numbers, but the energy of these events were smaller. Parallel crack patterns can be observed after dye penetration tests.