水基凝胶注模成型制备氧化铝陶瓷薄板的工艺研究

发布时间：2018-03-17 10:42

  本文选题：凝胶注模成型　切入点：氧化铝陶瓷板　出处：《济南大学》2015年硕士论文　论文类型：学位论文

【摘要】：水基凝胶注模成型工艺周期短,能近净尺寸成型不同形状的陶瓷,制备的陶瓷素坯强度高可机械加工,被广泛用于各类陶瓷研究和生产。本课题选用丙烯酰胺单体和明胶大分子这两种水基凝胶体系,制备氧化铝陶瓷板。通过研究确定各体系成型时的最佳工艺参数,以制备内部结构均匀、力学性能优良的氧化铝陶瓷板。对于丙烯酰胺单体体系,通过控制分散剂加入量、PH值、球磨时间制备出了固相含量高达54 vol%的氧化铝悬浮液。实验时,研究固相含量对坯体性能的影响,由大量实验确定坯体的干燥制度和排胶曲线,通过研究单体含量对陶瓷抗折强度和致密度及显微结构的影响,确定最佳单体添加量,由烧结温度对陶瓷微观结构和力学性能的影响,确定最佳烧结温度。结果表明,当固相含量54 vol%,分散剂含量1.2 wt%,PH=9,球磨时间6小时,单体含量2.7 wt%时,陶瓷素坯和烧结后的陶瓷性能最好,素坯抗折强度达到23.87 MPa、收缩率为1.99%。素坯经排胶后,在1640℃下烧结,测得陶瓷气孔率为1.78%、体积密度为3.64 g/cm3,抗折强度达到313.62 MPa,此时陶瓷致密度最高、性能最好。针对明胶体系,控制分散剂添加量、PH值、球磨时间和明胶含量制备出适宜注模的氧化铝悬浮液。测定固相含量与素坯力学性能及线收缩的关系,研究明胶含量及烧结温度对陶瓷性能和微观结构的影响。实验结果:固相含量50 vol%,分散剂含量1.0 wt%,PH=9,球磨时间5小时,明胶含量4.5 wt%时,陶瓷素坯和烧结后的陶瓷性能最好,素坯抗折强度达到5.69 MPa,收缩率为2.36%。在1640℃温度下烧结,陶瓷气孔率为3.24%、体积密度为3.60 g/cm3、抗折强度达到269.20 MPa,实验条件下所得陶瓷致密度最高、性能最好。由丙烯酰胺单体聚合体系所制备的氧化铝陶瓷板内部微观结构均匀性好,素坯强度高,可在素坯状态下机械加工。最佳工艺条件下制备的陶瓷板致密度高,显微结构均匀,几乎不存在气孔,该体系可推广到工业化生产;而明胶大分子体系制得料浆的最高固相含量仅为50 vol%,成型的陶瓷板材因明胶加热过程中的发泡作用,最终陶瓷微观结构不是很均匀,气孔率较大,力学性能差,有待进一步改善。
[Abstract]:The water-based gel injection molding process has a short period and can be used to form ceramics of different shapes in near net size. The prepared ceramic blank has high strength and can be machined by mechanical processing. It is widely used in the research and production of various kinds of ceramics. In this paper, two kinds of hydrogel systems, acrylamide monomer and gelatin macromolecule, are used to prepare alumina ceramic plate. Alumina ceramic plates with uniform internal structure and excellent mechanical properties were prepared. For acrylamide monomers, alumina suspensions with solid content of up to 54 volt% were prepared by controlling the amount of dispersant and adding PH value and milling time. The effect of solid content on the properties of the billet was studied. The drying system and the rubber discharge curve of the billet were determined by a large number of experiments. By studying the effect of monomer content on the flexural strength, density and microstructure of the ceramics, the optimum monomer content was determined. According to the effect of sintering temperature on the microstructure and mechanical properties of ceramics, the optimum sintering temperature is determined. The results show that when the solid content is 54 volr, the dispersant content is 1.2 wtmol / h, the milling time is 6 hours, the monomer content is 2.7 wt%. The properties of the raw and sintered ceramics are the best, the flexural strength of the blank is 23.87 MPa, the shrinkage is 1.99.The blank is sintered at 1640 鈩，

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