陶瓷无模直写成型技术的研究

发布时间：2018-05-09 19:06

本文选题：直写成型 + 流变性　；参考：《清华大学》2015年博士论文

【摘要】：基于流体浆料的直写成型技术是一种新型固体无模成型方法,在微米级以下高技术陶瓷的制备领域较传统的成型方法具有更大的潜力。与其他无模成型技术相比,直写成型能够在常温、无需任何模具或者紫外光、激光辐射的条件下制备三维多孔精细结构,拓宽了无模成型的应用领域。本文基于不同体系的陶瓷浆料探讨直写成型技术工艺流程及其相关应用。系统研究了陶瓷浆料直写成型的工艺流程,包括粉体的处理、浆料配制、结构成型、干燥烧结以及性能表征等环节。通过多种结构的设计显示和验证直写成型方法的灵活性。从溶剂的选择和分散剂的作用机理上,探讨了理想浆料的配制方法。从成型工艺参数上,分析了直写过程中的关键技术。以PLZT陶瓷粉体为原料,通过直写成型制备了多种形状的三维结构,对比了不同溶剂体系下,浆料的流变学特征以及最小特征尺寸。以PLZT木堆结构为骨架,填充环氧树脂制备3-3型PLZT-Epoxy复合材料,测试其电学性能,静水压灵敏度因子dhgh值最大可达4112×10-15m2/N,大于块体PLZT陶瓷(365×10-15m2/N),也高于注射法制备的3-3型PZT复合材料(4020×10-15m2/N)。以无铅压电陶瓷KNN粉体为原料制备三维结构,测试其电学性能,充分体现了直写成型在制备三维器件上的设计灵活性。以Ti O2和α-Fe_2O_3粉体为原料,基于直写成型方法制备三维多孔催化剂器件。通过不同堆积方式的结构设计,证实了结构对光催化效率的影响。直写技术制备的多孔催化剂光降解效率高于传统成型方法制备的块体催化剂,体现了直写成型技术在制备高效率多孔催化剂上的巨大优势。以无水乙醇为主要溶剂,混合凡士林配制羟基磷灰石浆料,通过直写成型制备出三维生物陶瓷支架。在羟基磷灰石支架周围接种Hep G2细胞,验证其生物相容性。直写技术可以通过控制孔洞的大小和形状诱导细胞增殖。以去离子水为溶剂,柠檬酸铵为分散剂制备Zr O2浆料,基于直写成型技术制备三维多孔组织工程支架。通过抗压强度测试,探讨了多孔结构的孔隙率与抗压强度的关系。通过接种HCT116细胞,证实了Zr O2支架的生物相容性。与羟基磷灰石对比,证明Zr O2支架的良好机械性能,有望用于承重骨骼的修复。
[Abstract]:The direct-writing technology based on fluid slurry is a new kind of solid mold forming method. It has more potential than traditional molding methods in the field of preparing high-tech ceramics below micron level. Compared with other molding techniques, direct writing can fabricate three-dimensional porous fine structures at room temperature, without any mold or ultraviolet radiation, and broaden the application field of mouldless molding. Based on the different systems of ceramic slurry, this paper discusses the process flow of direct-writing molding technology and its related applications. The process flow of direct writing of ceramic slurry was studied systematically, including powder treatment, slurry preparation, structure molding, drying sintering and performance characterization. The flexibility of the direct writing molding method is demonstrated and verified by the design of various structures. Based on the selection of solvent and the action mechanism of dispersant, the preparation method of ideal slurry was discussed. The key technologies in the process of direct writing are analyzed from the point of view of forming process parameters. Using PLZT ceramic powder as raw material, three dimensional structures with various shapes were prepared by direct writing. The rheological characteristics and minimum characteristic size of slurry were compared in different solvent systems. 3-3 type PLZT-Epoxy composites were prepared by filling epoxy resin with PLZT wooden pile structure. The electrical properties of 3-3 PLZT-Epoxy composites were tested. The maximum hydrostatic sensitivity factor (dhgh) was 4112 脳 10 ~ (-15) m ~ (2 / N), which was higher than that of bulk PLZT ceramics (36.5 脳 10 ~ (-15) m ~ (2 / N) / N), and was higher than that of 3-3 PZT composites prepared by injection method (4020 脳 10 ~ (-15) m ~ (-2) / N ~ (-1). Three-dimensional structure was prepared from lead-free piezoelectric ceramic KNN powder, and its electrical properties were tested, which fully demonstrated the design flexibility of direct-writing molding in the fabrication of three-dimensional devices. Three-dimensional porous catalyst devices were prepared from TIO _ 2 and 伪 -Fe _ 2O _ 3 powders based on direct writing. The effect of structure on photocatalytic efficiency was confirmed by the structural design of different stacking methods. The photodegradation efficiency of the porous catalyst prepared by direct writing technology is higher than that of bulk catalyst prepared by traditional molding method, which shows the great advantage of direct writing technology in the preparation of high efficiency porous catalyst. Hydroxyapatite paste was prepared by mixing vaseline with anhydrous ethanol as the main solvent. Three-dimensional bioceramic scaffold was prepared by direct writing. Hep G2 cells were inoculated around hydroxyapatite scaffolds to verify their biocompatibility. Direct writing can induce cell proliferation by controlling the size and shape of holes. ZrO 2 slurry was prepared by using deionized water as solvent and ammonium citrate as dispersant. Three-dimensional porous tissue engineering scaffold was prepared based on direct-writing technology. The relationship between porosity and compressive strength of porous structure is discussed by means of compressive strength test. The biocompatibility of ZrO 2 scaffold was confirmed by inoculating HCT116 cells. Compared with hydroxyapatite, the ZrO _ 2 scaffold has good mechanical properties and is expected to be used in the repair of load-bearing bone.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TQ174.62

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