注凝成型工艺制备熔融石英陶瓷过程的研究

发布时间：2018-04-03 16:12

  本文选题：注凝成型　切入点：熔融石英陶瓷　出处：《湖南工业大学》2017年硕士论文

【摘要】：熔融石英陶瓷因其优异的抗热震性、低的热膨胀系数和低的热导率,被广泛的应用在航空、电子、太阳能等领域,但传统工艺制备的熔融石英陶瓷普遍存在致密性低、气孔率高等缺陷,阻碍了它的更广泛的应用。本论文主要对采用注凝成型工艺制备高强度、高致密性的熔融石英陶瓷的过程进行了系统研究,并对陶瓷生坯制备、烧结等各工艺步骤的影响因素进行了优化和分析。本实验以高纯熔融石英粉为主要原料,采用低毒的甲基丙烯酸羟基乙酯(HEMA)/三羟甲基丙烷三丙烯酸酯(TMPTA)体系,分散剂是聚丙烯酸铵(NH4PAA),用乳酸调节pH值,引发剂和催化剂分别为过硫酸铵溶液(APS)、四甲基乙二胺(TEMED),添加Si_3N_4作为烧结助剂,最后利用微波烧结生坯。通过对陶瓷料浆的粘度测试,结合万能材料试验机、X射线衍射(XRD)、扫描电子显微镜(SEM)、电子密度计等表征方法对样品进行检测和分析。实验结果表明,当料浆的固相含量为60vol%、pH值为4、分散剂添加量为1.5wt%、超声波振动时间为20min时,料浆的分散性、流动性最稳定;单体添加量为8wt%、交联剂的加入量为4wt%、引发剂量为0.2wt%时,固化时间为30min,生坯的抗弯强度最高能达到16.5MPa;采用微波烧结时,添加量为1.5wt%Si_3N_4助剂,在升温速率为20℃/min、烧结温度为1150℃,保温时间时间为2h时,烧制的样品的抗弯强度最高能达到36.3MPa,体积密度能达到1.98g/cm3,性能得到了进一步的提升,实验达到了预期的结果。
[Abstract]:Fused quartz ceramics are widely used in aviation, electronics, solar energy and other fields because of their excellent thermal shock resistance, low thermal expansion coefficient and low thermal conductivity.High porosity and other defects hinder its wider application.In this paper, the process of preparing fused quartz ceramics with high strength and high density by injection molding process was studied systematically, and the factors affecting the preparation and sintering of ceramic blank were optimized and analyzed.In this experiment, the high purity fused quartz powder was used as the main raw material, the low toxic hydroxyl ethyl methacrylate (Hema) / trimethylol propane triacrylate (TMPTAA) system was used, the dispersant was ammonium polyacrylate (NH4PAAN), and the pH value was adjusted with lactic acid.The initiator and catalyst were ammonium persulfate solution and tetramethyl ethylenediamine respectively, and Si_3N_4 was added as sintering assistant. Finally, the billet was sintered by microwave.The viscosity of ceramic slurry was measured and analyzed by means of X-ray diffraction, scanning electron microscope (SEM), electron densitometer and so on.When the curing time is 30 min, the maximum bending strength of the billet is 16.5 MPa, when microwave sintering is used, the amount of 1.5wt%Si_3N_4 is added, the heating rate is 20 鈩，

本文编号：1705934