【摘要】：AlN陶瓷具有高熱導率、優(yōu)異的絕緣性能和介電性能、強抗腐蝕能力以及與硅相匹配的熱膨脹系數(shù)等特點,被廣泛用作電子封裝材料、壓電器件、保護涂層和透明陶瓷等方面。本研究采用凝膠注模成型技術制備AlN陶瓷,主要研究三羥甲基丙烷三縮水甘油醚(TMPGE)乙醇溶液凝膠反應規(guī)律,制備具有高固相含量、低粘度的AlN漿料,研究AlN坯體凝膠注模成型工藝和坯體固含量對AlN陶瓷性能的影響。主要研究內容如下:(1)研究TMPGE凝膠體系反應動力學。實驗結果表明,升高溫度和提高TMPGE濃度都能提高凝膠反應速率,不同TMPGE濃度的乙醇溶液凝膠反應活化能變化不大,都在40~50 kJ/mol之間。(2)研究分散劑、固含量和球磨時間對Al N漿料粘度的影響。實驗測得分散劑濃度在0.6 wt%時,球磨時間為24 h時,固含量為45 vol%AlN漿料的粘度最小為22mPa·s。AlN漿料粘度隨著固含量的增加而升高,固含量達到54 vol%時AlN漿料粘度為244 mPa·s。(3)采用正辛醇化學消泡和真空攪拌物理消泡相結合的手段除氣,在高乙醇濕度環(huán)境下進行干燥得到表面平整光滑的AlN生坯。(4)實驗制得體積固含量為54 vol%,生坯相對密度達65.8%,線收縮率僅為2.5%,抗彎強度最高為10.31 MPa,顆粒分布均勻致密的AlN生坯,并研究固含量和環(huán)氧樹脂含量對生坯性能的影響。實驗結果表明,隨著固含量的增加,坯體密度增加,線收縮率和抗彎強度減小,顯微結構逐漸致密。隨著環(huán)氧樹脂含量的增加,坯體抗彎強度增加,孔隙減少,氮化鋁顆粒排列越來越緊密。(5)采用1℃/min緩慢升溫至580℃保溫1 h排膠,在N2氣氛下、1800℃保溫6 h對排膠后AlN坯體進行燒結,制備出相對密度達到99.67%的AlN坯體。對AlN燒結體進行物相分析,研究固含量對燒結體密度、顯微結構和力學性能的影響。結果表明,隨著固含量的增加,AlN燒結體密度逐漸增加,抗彎強度先增大后減小,抗彎強度最高達305MPa。
[Abstract]:AlN ceramics are widely used as electronic packaging materials, piezoelectric devices, protective coatings and transparent ceramics for their high thermal conductivity, excellent insulation and dielectric properties, strong corrosion resistance and thermal expansion coefficient matching with silicon. In this paper, AlN ceramics were prepared by gel injection molding technology. The gelling reaction of trimethylolpropane triglycidyl ether (TMPGE) ethanol solution was studied. The AlN slurry with high solid content and low viscosity was prepared. The effects of gel injection molding technology and solid content of AlN billet on the properties of AlN ceramics were studied. The main contents are as follows: (1) the reaction kinetics of TMPGE gel system was studied. The results show that the gel reaction rate can be increased by increasing the temperature and the concentration of TMPGE, and the activation energy of the gel reaction in ethanol solution with different TMPGE concentration has little change, ranging from 40 to 50 kJ/mol. (2) the dispersant was studied. Effects of solid content and milling time on viscosity of Al N slurry. When the concentration of dispersant is 0.6 wt% and the milling time is 24 h, the viscosity of 45 vol%AlN slurry is minimum and the viscosity of 22mPa s.AlN slurry increases with the increase of solid content. When the solid content reaches 54 vol%, the viscosity of AlN slurry is 244 mPa s. (3). AlN billet with smooth surface was obtained by drying under high ethanol humidity. (4) the relative density of bulk solid content of 54 vol%, blank was 65.8, and the linear shrinkage rate was only 2.5%. The maximum flexural strength was 10.31 MPa, particles distributed uniformly and densified AlN green billet. The effects of solid content and epoxy resin content on the properties of green billet were studied. The experimental results show that with the increase of solid content, the density of the billet increases, the linear shrinkage and bending strength decrease, and the microstructure becomes denser. With the increase of epoxy resin content, the flexural strength of the billet body increases, the porosity decreases, and the aluminum nitride particles are arranged more and more tightly. (5) 1 鈩，

本文編號：2340512