標題: 氧化鋁-氧化鈣-氧化鋯三元複合材料與鈦金屬高溫擴散介面反應
Interfacial Reactions between Titanium and Alumina/Calcium/Zirconia Ternary Composites at 1550°C
作者: 林健正
LIN CHIEN-CHENG
國立交通大學材料科學與工程學系(所)
關鍵字: 氧化鋁;氧化鈣;氧化鋯;鈦金屬;介面反應;鋯酸鈣;Al2O3;CaO;ZrO2;CaZrO3;Titanium
公開日期: 2011
摘要: 鈦合金之精密鑄造係採用電弧熔融法(vacuum arc melting, VAR, 一名skull melting, 骸式熔融 法),以水冷式銅坩鍋盛裝鈦融液,在坩鍋壁上產生凝固層,以保護銅坩鍋,惟此法的液態鈦金屬流 動性不良,故多以離心鑄造法進行鈦合金之鑄造。 鈦金屬在熔融時是一種活性極強的金屬,直接與陶瓷模接觸,易在介面發生劇烈反應,產生表面 硬化層,常是鑄件產生裂縫成長的起始點。因此,一般在鑄件完成後會以化學溶液洗蝕或噴砂法除去 表面硬化層,如此不僅增加成本,亦影響鑄件精密度。欲選用最適合的坩堝與陶模材料應用於精密鑄 造,應先瞭解鈦合金與陶瓷的介面反應,並有效控制之。 本實驗室過去已研究氧化鋯與鈦金屬的介面反應機構,並探討氧化釔含量與氧化鈣含量對介面反 應的影響,其中氧化釔含量對介面反應的影響已經有非常重要的成果發表於美國陶瓷學會期刊上,經 由實驗室建立Ti 和不同組成Y2O3/ZrO2 的基礎文獻可發現當Y2O3 添加量大於30 vol%時可以有效地抑 制Ti 側的介面反應,然而Y2O3 價格昂貴,因此利用CaO 取代Y2O3 以降低成本,發現17 mol% CaO 全安定氧化鋯於鈦側生成CaZrO3 以抑制Ti 擴散。 本實驗研究以抗介面反應性質優異之17 mol%CaO + 83 mol%ZrO2 為基準,嘗試加入Al2O3 以進一 步地降低材料的成本,探討Al2O3/CaO/ZrO2 三元複合材料與鈦金屬高溫擴散的介面反應機制,並且調 整Al2O3 的含量,檢視是否存在一個門檻,在Al2O3 含量在一定比例以下,仍保有優異之抗介面反應 特性。 本實驗以熱壓法製備Al2O3/CaO/ZrO2 三元複合材料試片,在陶瓷試片與鈦在高溫介面反應後,以 x-ray 繞射儀、熱場發射掃瞄式電子顯微鏡及能量分散能譜儀(FESEM/EDS)、電子微探分析儀 (EPMA)、穿透式電子顯微鏡能量分散能譜儀(TEM/EDS)等分析鈦金屬與陶瓷間反應介面之微觀 結構,並探討微結構的演化和每一個相的生成機構以及Al2O3 含量對CaO+ZrO2 三元複合材料與鈦金 屬高溫擴散介面反應的影響。
Titanium is usually melted in a water-cooled copper crucible by the consumable electrode vacuum arc melting (VAR) instead of vacuum induction melting (VIM) because the ceramic crucible, used in the VIM process, seriously reacts with titanium melt. In addition, the surfaces of titanium castings are required to be chemically milled in order to remove the reaction products between Ti castings and ceramic molds. Therefore, how to control the interfacial reactions between titanium and ceramics is of great concern. The interfacial reactions between Ti and ZrO2 have been subjected to intensive studies in the last few years. Furthermore, the effect of yttria was conducted on the interfacial reactions between Ti and hot pressed Y2O3/ZrO2 mixtures. Our previous important results were published in the Journal of the American Ceramic Society. In this study, the powder mixtures of Al2O3/CaO/ZrO2 will be hot-pressed and then allowed to react with titanium at 1700°C for 1 h in argon. Various reaction layers at the interface between titanium and Al2O3/CaO/ZrO2 composites will be characterized using an analytical scanning electron microscope, an electron probe microanalyzer, and an analytical transmission electron microscope. After the effect of Al2O3 on the interfacial reactions between Ti and Al2O3/CaO/ZrO2 ternary composites is fully explored, the ratio of Al2O3/CaO/ZrO2 can be optimized to achieve a better control over the interfacial reactions.
官方說明文件#: NSC100-2221-E009-067-MY2
URI: http://hdl.handle.net/11536/99394
https://www.grb.gov.tw/search/planDetail?id=2335281&docId=367225
顯示於類別:研究計畫