氮化铝凝胶注模成型工艺研究
发布时间：2018-11-18 16:15
【摘要】：AlN陶瓷具有高热导率、优异的绝缘性能和介电性能、强抗腐蚀能力以及与硅相匹配的热膨胀系数等特点,被广泛用作电子封装材料、压电器件、保护涂层和透明陶瓷等方面。本研究采用凝胶注模成型技术制备AlN陶瓷,主要研究三羟甲基丙烷三缩水甘油醚(TMPGE)乙醇溶液凝胶反应规律,制备具有高固相含量、低粘度的AlN浆料,研究AlN坯体凝胶注模成型工艺和坯体固含量对AlN陶瓷性能的影响。主要研究内容如下:(1)研究TMPGE凝胶体系反应动力学。实验结果表明,升高温度和提高TMPGE浓度都能提高凝胶反应速率,不同TMPGE浓度的乙醇溶液凝胶反应活化能变化不大,都在40~50 kJ/mol之间。(2)研究分散剂、固含量和球磨时间对Al N浆料粘度的影响。实验测得分散剂浓度在0.6 wt%时,球磨时间为24 h时,固含量为45 vol%AlN浆料的粘度最小为22mPa·s。AlN浆料粘度随着固含量的增加而升高,固含量达到54 vol%时AlN浆料粘度为244 mPa·s。(3)采用正辛醇化学消泡和真空搅拌物理消泡相结合的手段除气,在高乙醇湿度环境下进行干燥得到表面平整光滑的AlN生坯。(4)实验制得体积固含量为54 vol%,生坯相对密度达65.8%,线收缩率仅为2.5%,抗弯强度最高为10.31 MPa,颗粒分布均匀致密的AlN生坯,并研究固含量和环氧树脂含量对生坯性能的影响。实验结果表明,随着固含量的增加,坯体密度增加,线收缩率和抗弯强度减小,显微结构逐渐致密。随着环氧树脂含量的增加,坯体抗弯强度增加,孔隙减少,氮化铝颗粒排列越来越紧密。(5)采用1℃/min缓慢升温至580℃保温1 h排胶,在N2气氛下、1800℃保温6 h对排胶后AlN坯体进行烧结,制备出相对密度达到99.67%的AlN坯体。对AlN烧结体进行物相分析,研究固含量对烧结体密度、显微结构和力学性能的影响。结果表明,随着固含量的增加,AlN烧结体密度逐渐增加,抗弯强度先增大后减小,抗弯强度最高达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，
本文编号：2340512
[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，
本文编号：2340512
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