氧化釔/氧化鋯複合材料與液態鈦金屬之介面反應

Abstract

以熱壓法製備不同組成之Y2O3/ZrO2(Yttria/Zirconia)複合材料，與鈦(Titanium, Ti)在1atm 氬(Ar)氣氛下，進行1700°C/10min之擴散反應，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)、電子微探儀(electron probe microanalyzer, EPMA)與穿透式電子顯微鏡(transmission electron microscopy/energy dispersive spectroscopy, TEM/EDS)，分析擴散反應後介面之微觀結構。結果顯示10 vol%Y2O3-ZrO2複合材料與鈦發生劇烈的擴散反應，鋯與氧大量固溶於鈦中，反應生成物從鈦側至陶瓷側依序為α-Ti(Zr, O)、β'-Ti(Zr, O)與針狀α-Ti二相區、以及大量的α-Zr。Y2O3體積含量大於30 vol%時，界面擴散反應明顯受到抑制，鈦液僅能沿晶界與孔隙滲入陶瓷側，冷卻後形成網狀分佈的α-Ti(Zr, O)與β'-Ti(Zr, O)二相區，同時鈦側β'-Ti(Zr, O)與陶瓷側α-Zr的生成量隨Y2O3含量的增加而減少。Y2O3體積含量大於70 vol%時，鈦液滲入陶瓷側的路徑大部分被阻斷，冷卻後形成塊狀分佈的α-Ti(Zr, O)與β'-Ti(Zr, O)二相區。Y2O3體積含量大於90 vol%時，鈦、鋯擴散反應幾乎完全被抑制，界面處無反應層出現。

Hot pressed composites with various content of Y2O3 and ZrO2 were reacted with the titanium melt at 1700°C/10min in argon. The microstructure of the reaction interface were characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalyzer (EPMA) and analytical transmission electron microscopy (TEM/EDS). The result showed that an obviously diffusive phenomenon occur in the 10vol% Y2O3-ZrO2 composite and titanium. The α-Ti(Zr, O) and β'-Ti(Zr, O) formed in the titanium side during cooling down to the room temperature. The β'-Ti(Zr, O) existed due to the dissolution of large amount of Zr which restrained β→α phase transformation. In the ceramic side, large amount of α-Zr was precipitate from ZrO2-x. When the Y2O3 content is greater then 30vol%, the diffusive phenomenon was restrained. The liquid titanium can only infiltrated into the ceramic mold through the open pores and grain boundary. The α-Ti(Zr, O) and β'-Ti(Zr, O) formed in the ceramic side in the form of network during cooling down to the room temperature. Precipitation of β'-Ti(Zr, O) in titanium side and α-Zr in ceramic side decrease as the Y2O3 content increase. When the Y2O3 content is greater then 70vol%, infiltration path of liquid titanium to ceramic side was mostly blocked. When the Y2O3 content is greater then 90vol%, there is no interfacial reaction zone between titanium and ceramic composite.