氧化鋯內添加不同比例氧化鈣與鈦金屬高溫擴散

Abstract

以熱壓法製備不同組成之CaO/ZrO2(Calcia/Zirconia)陶瓷試片，與鈦(Titanium, Ti)在1atm 氬(Ar)氣氛下，進行1550℃/6 hr之擴散反應，探討CaO含量對CaO/ZrO2系陶瓷材料與鈦金屬高溫擴散介面反應之影響。本實驗利用X光繞射(x-ray diffraction, XRD)、掃描式電子顯微鏡(Scanning Electron Microscopy/Energy Dispersive Spectroscopy, SEM/EDS)，分析擴散反應後介面之微觀結構。實驗結果顯示，在5mole％ CaO/ZrO2與鈦高溫擴散反應後，介面擴散反應受到抑制，鈦側發現僅有一層反應層，厚度約2μm之TiO反應層，而在氧化鋯側發現有大量的α-Zr與t-ZrO2-x的產生，可知反應層TiO的產生像一層擴散阻擋(barrier)層，使Ti、Zr的擴散明顯受到抑制。

CaO/ZrO2陶瓷試片9mole％與17mole％，分別與鈦高溫擴散反應後，發現Ti與Zr之間有相當劇烈的擴散反應，而Zr、O大量固溶於Ti中，在鈦側發現有三層反應層，依序為α-Ti＋Ti2ZrO、β΄-Ti＋α-Ti＋Ti2ZrO及β΄-Ti＋acicular α-Ti，而在氧化鋯側接近介面處則發現有β΄-Ti與CaZrO3共存，而在遠離介面處之陶瓷側影響區則有大量α-Zr與c-ZrO2-x的產生。但在17mole％ CaO/ZrO2中，在遠離介面之陶瓷影響區，除了有α-Zr與c-ZrO2-x的產生，有少量CaZrO3會存在於晶界上。在陶瓷側α-Zr析出量隨CaO含量增加而有明顯減少。

Various CaO/ZrO2 hot press sample was reacted with titanium at 1550℃/6 hr. in argon Investigate the ratio of the CaO/ZrO2 can be effective to control the interfacial reaction. The microstructure of the reaction interface was characterized using x-ray diffraction(XRD) and analytical electron microscopy(SEM/EDS).

A few reactions take place at interface between Ti and 5mole％ CaO/ZrO2. Interfacial reactions were effectively suppressed by incorporating less than 5mole％ CaO. TiO reaction layer effectively obstruct Ti and Zr diffuse mutually. TiO layer function was like a reaction barrier phase and found in the Ti side. 9mole％ and 17mole％ CaO/ZrO2 react with Ti at 1550℃ 6 hr gave rise to strong reaction. A large amount of Zr and O was dissolved into Ti . Product three reactive layers of α-Ti＋Ti2ZrO、β΄-Ti＋α-Ti＋Ti2ZrO及β΄-Ti＋acicular α-Ti in the Ti side. And on the zirconia side near the original interface were found β΄-Ti and CaZrO3 coexist, result in Ti and Ca cannot mutual solubility. In region of far away the original interface, α-Zr, c-ZrO2-x, and/or residual CaZrO3 were found in the ceramic side. More than 17mole％ CaO/ZrO2 the amount of α-Zr decreased with increasing CaO.