- 期刊
製備堇青石與氮化鋁複合材料之燒結性質研究
On the Preparation and Sintering Properties of Cordierite and Aluminum Nitride Composites
摘要
本研究以硝酸鎂、硝酸鋁、TEOS（矽酸乙酯）為起始原料，溶膠－凝膠法製備堇青石粉末。為了提高堇青石熱傳導性質，以濕混方式分別添加0 wt%～30 wt%氮化鋁粉末，由於氮化鋁於高溫下容易氧化生成氧化鋁，本研究以碳黑與氮化硼作為空氣阻隔劑，有別於一般以還原氣氛爐燒結之製程。此外，由於氮化鋁燒結溫度過高且堇青石燒結不易，故本研究添加氧化鉍為燒結助劑，以期製備緻密之堇青石－氮化鋁陶瓷燒結體。研究結果顯示煆燒溫度對堇青石粉末粒徑影響不大，主要造成相變的產生，μ-堇青石相變為α-堇青石的溫度約為1300℃。添加10 wt%氮化鋁於1250℃持溫6小時之燒結體 可得到最高相對密度96.65%、線收縮率27.27%。堇青石－氮化鋁燒結體介電係數均介於4～6，符合低介電材料需求，添加15 wt%氮化鋁之燒結體可得到最佳品質因子2592.7（1MHz）。添加10 wt%氮化鋁於1350℃持溫6小時之燒結體可得到最高熱傳導係數，其值為8.14W/mK。
並列摘要
The cordierite was synthesized with magnesium nitrate, aluminum nitrate, and tetraethyl orthosilicate by sol-gel method. The composite was made by mixing cordierite with 0 wt%~30 wt% AlN to promote the thermal conductivity. The ceramic body was buried with carbon black and boron nitride to avoid oxidation of AlN in high temperature environment. Bismuth oxide was used as sintering aids to decrease the sintering temperature of AlN and cordierite composites. Results showed that the calcination temperature is influential in controlling the cordierite phase transition, but not cordierite grain size. The temperature μ-cordierite phase transited to α-cordierite phase was 1,300℃. The composites with 10 wt% AlN sintered at 1,250℃ for 6 h had the highest relative density of 96.7% and linear shrinkage 27.3%. All composites had the dielectric constant between 4~6 in a range required for low dielectric constant materials. The composites with 15 wt% AlN had the best quality factor 2592.7(1MHz). The composites with 10 wt% AlN sintered at 1,350℃ for 6 h had the best thermal conductivity of 8.14W/mK.