鋯酸鈣/氧化釔複合材料與液態鈦合金(Ti-6Al-4V)之介面反應

Abstract

CaZrO3/Y2O3依照不同體積比混合後，經過1500℃/30min熱壓成陶瓷複合材料試片，並與鈦合金(Ti-6Al-4V)在1atm氬(Ar)氣氛下，進行1700℃/30min之高溫擴散反應，探討在此製程參數下，陶瓷材料與鈦合金高溫擴散反應介面之影響。本實驗用X光繞射儀(x-ray diffraction, XRD)、掃描式電子顯微鏡(SEM/EDS)，分析擴散後的介面反應微觀結構。 研究結果發現CaZrO3以及Y2O3在高溫熱處理過程中除了相互固溶形成固態溶液外，在相互反應上皆十分安定。而純CaZrO3則是會與Ti-6Al-4V產生不太顯著的介面反應，是唯一一組在金屬側產生多層反應層的試片。然而添加了Y2O3的複合材料熔煉後，在金屬側以及陶瓷側的介面處會生成一層以Y2O3為基底之反應層而有效抑制介面反應，其反應層的厚度隨著Y2O3含量增加而增加，相對的抑制介面反應的效果也更加顯著。當Y2O3的含量達到90 vol%以上時即可視為Y2O3直接和Ti-6Al-4V反應因而十分穩定，為所有試片中唯一不反應的一組，顯示Y2O3相對於CaZrO3來說擁有更良好的安定性。

Various composites of CaZrO3 and Y2O3 were hot pressed at 1500°C /30 MPa for 30 min and then reacted with titanium alloy (Ti-6Al -4V) at 1700°C/30 min. The microstructure of the reaction interface was characterized and analyzed using x-ray diffraction (XRD) and scanning electron microscopy (SEM/EDS). The XRD spectra only for the as hor pressed ceramic composites indicated that CaZrO3/Y2O3 were stable during the heat treatment, and no new compound were found except solid solution. Pure CaZrO3 had slightly reaction with Ti-6Al-4V, and it’s the only one sample formed more than one reaction layer in the metal side. A reaction layer, which consisting of Y2O3 were formed and then was suppressed the interaction between titanium alloy and composites. Besides, The thickness of this reaction layer increased with increasing Y2O3, and obviously less interaction happened. When the content of Y2O3 was increased up to 90 vol%, it was behavior as a pure Y2O3 contact with Ti-6Al-4V, there were no reaction between each other. It seems that Y2O3 had higher stability and thus a better material for the mold of molten titanium alloy compared with CaZrO3.