氧化鋁含量對鋯酸鈣/氧化鋁複合材料與鈦金屬介面反應之影響

Abstract

本研究將不同比例的氧化鋁添加入自製的鋯酸鈣粉末中並以1500°C/30MPa/30分鐘的條件熱壓成複合材料後，與Cp-Ti在1 atm 氬氣氛下，進行1600°C/30分鐘的高溫介面反應，並以X光繞射儀(XRD)和掃描式電子顯微鏡(SEM/EDS)來進行微觀結構的分析及鑑定。 從研究結果觀察到氧化鋁添加量上升，在陶瓷側出現的二鋁酸鈣(CaAl4O7)與立方晶氧化鋯(c-ZrO2)隨之增加，鈦側的反應層則逐漸減少所觀察到的反應層有：α-Ti(Zr, O)、β'-Ti(Zr, O)、Ti3Al…等相。在複合材料樣品中，鋯酸鈣的比例隨著氧化鋁含量的增加而降低，立方晶體氧化鋯比例反而增加。其原因為氧化鋁較容易與氧化鈣反應形成二鋁酸鈣，使得鋯酸鈣會因此分解出氧化鋯。當氧化鋁添加量大於25 mol%會觀察到有一層緻密的鋯酸鈣產生，其為抑制介面反應的主要相。

The samples were prepared with various content of ball-milled CaZrO3 and Al2O3 at different mole percent, then hot-pressed at 1500˚C for 30 minutes and reacted with Cp-Ti at 1600˚C for 30 minutes. The as-hot-pressed samples and interfacial reaction were characterized using x-ray diffraction (XRD) and scanning electron microscopy (SEM/EDS). The XRD spectra indicated that with the increase of Al2O3 there existes more CaAl4O7 and c-ZrO2 phases. For the titanium side there exists α-Ti(Zr, O), β'-Ti(Zr, O), Ti(Al) phases. The phases of CaAl4O7 and c-ZrO2 were increased with the increasing amount of Al2O3, due to the reaction of Al2O3 and CaZrO3 causing the formation of CaAl4O7 and remaining ZrO2. According to SEM/EDS results with the Al2O3 increasing to 25 mol.% or more will cause a compact layer of CaZrO3 to occur which is believed to be the reason to control the diffusion of ZrO2 to the titanium side.