氧化鋯與鈦金屬高溫擴散反應之介面微觀結構分析

Abstract

本實驗先以熱壓法製備3mol%Y2O3- ZrO2，使之與Ti在1250℃~1550℃進行擴散接和反應，並利用XRD、SEM/EDS、EPMA、TEM/EDS等來分析介面微觀結構，結果顯示在1550℃下，在介面處會有α-Ti(Zr,O)的結構，在陶瓷側有固溶鈦的氧化鋯晶粒會較無固溶鈦的氧化鋯晶粒為小，而由於鈦與氧的親和力大，故在陶瓷側會有部分氧融入鈦中形成α-Ti(O)，使得ZrO2還原成ZrO2-x，而板狀α-Zr(O)會從陶瓷側的缺氧氧化鋯(ZrO2-x)中析出，其中板狀α-Zr(O)具有雙晶平面，在1550℃所形成之缺氧氧化鋯(ZrO2-x)經TEM鑑定為cubic結構，鈦與氧化鋯經過1550℃/3hr的介面反應後，金屬側會有泡棉狀結構產生，而鈦與氧化鋯經過1550℃/0.5hr的介面反應後，金屬側則只有一層α-Ti (Zr,O)的反應層，無泡棉狀結構產生，而鈦與氧化鋯1400℃/3hr的介面反應後，在陶瓷側的氧化鋯的晶粒大小分佈亦是由介面處向遠離介面處遞增，在金屬側也有泡棉狀結構產生，但在1400℃/0.5hr介面反應後金屬側則無發現泡棉狀結構產生，而在1250℃/3hr的介面反應後，氧化鋯與鈦的反應為最不顯著。

Microstructure Characterization of the Reaction Zone in the Ti/Zirconia Diffusion Couple Student : Chung-Chi Yu Advisor : Chien-Cheng Lin Department of Material Science and Engineering National Chiao Tung University Abstract In the study, the specimen, 3 mol%Y2O3-ZrO2, was prepared by hot press method ,and reacted with Titanium at 1250℃~1550℃ by diffusion bonding. The interfacial microstructure were analyzed by XRD、SEM/EDS、EMPA、TEM/EDS. The results showed that □-Ti(Zr,O) was produced at the interface at 1550℃. The grain size of zirconia with solid-solution titanium was than that of zirconia without solid solution titanium in the ceramic side. The chemical affinity was strong between titanium and oxygen; therefore, the □-Ti (O) was formed by part of the oxygen dissolved in titanium. The ZrO2 was reduced into ZrO2-x by titanium, furtheymore, lath plate □-Zr(O) was precipitated from oxygen deficient zirconia in the ceramic side, and possessed twin plan structure. The oxygen deficient zirconia characterized by TEM, was a cubic structure formed at 1550℃.The interfacial reaction between titanium and zirconia produced sponge structure for 3hr at 1550℃ in the metal side.; on the contrary, only a reaction layer of □□-Ti (Zr,O) was form for 0.5hr at same temperature in the metal side. The grain size of zirconia was increased with away from the interface in the ceramic side. The sponge structure was also formed at 1400℃/3hr. No sponge structure was observed at the interface by the metal side at 1400℃/0.5hr. The reaction between titanium and zirconia was seldom occurred at the interface at 1250℃/3hr.