【作者】 黄芳；

【导师】 何惠明； 吴舜；

【作者基本信息】 第四军医大学 ， 口腔修复学， 2009， 硕士

【摘要】 氟硅云母玻璃陶瓷具有全瓷材料的优点,同时还具有优良的可切削性,成为与齿科CAD/CAM相匹配的全瓷修复材料,但其低强度低韧性限制了它在临床的广泛应用。因此现在的研究主要集中在既能保留氟硅云母玻璃陶瓷优良的生物相容性、可切削性能,又能最大程度提高强度和韧性,使其满足临床需要。近年来,为了提高陶瓷材料的强度和韧性,ZrO2增韧的复合陶瓷材料成为研究的热点。本文的指导思想是在氟硅云母玻璃陶瓷中添加ZrO2来提高基质玻璃的强度和韧性,为后续研究提供实验室依据。研究内容与方法:1.于氟硅云母基质玻璃中添加ZrO2的同时,将熔融法和烧结法两种工艺进行了对比,以扫描电镜(SEM)、X射线衍射(XRD)等分析手段对材料的物相组成及微观结构进行观察,通过测定三点弯曲强度和断裂韧性来反映其力学性能,选出何种工艺更适合添加ZrO2粉体,为下一步研究确定技术路线。2.采用烧结法添加等量(25wt%)、不同粒度ZrO2(50 nm和10μm)粉体来制备氟硅云母玻璃陶瓷复合材料,研究不同粒度ZrO2与复合材料的力学性能与微观结构间的关系。3.选用纳米ZrO2(50nm),采用烧结法添加不同质量(5wt%、10wt%、20wt%、30wt%)的ZrO2粉体来制备氟硅云母玻璃陶瓷复合材料,讨论不同含量ZrO2对氟硅云母玻璃陶瓷力学性能的影响。研究结果:1.采用熔融法和烧结法加入5wt%ZrO2后,氟硅云母玻璃陶瓷复合材料的抗弯强度和断裂韧性都有不同程度的提高,熔融法制备的复合材料三点抗弯曲强度达到128.5±12.1MPa,断裂韧性为1.62±0.06MPa·m1/2,烧结法制备的复合材料三点抗弯曲强度达到134.4±10.2MPa,断裂韧性为1.88±0.16MPa·m1/2。2.纳米组抗弯强度达到220.8±9.30MPa,断裂韧性达到2.54±0.10MPa·m1/2。纳米组和微米组间三点抗弯曲强度、断裂韧性均有统计学意义(P<0.05)。3.当纳米氧化锆含量为30%时,三点抗弯曲强度达到224.3±10.30MPa,断裂韧性为2.80±0.13MPa·m1/2。添加5wt%与10wt% ZrO2所制备的复合材料之间三点抗弯曲强度、断裂韧性无显著性差异(P>0.05),其余各实验组两两间有显著性差异(P<0.05)。实验结论:1.采用烧结法制备的氧化锆增韧的氟硅云母玻璃陶瓷力学性能比熔融法有所提高。2.添加纳米和微米ZrO2增韧的氟硅云母玻璃陶瓷复合材料,纳米ZrO2增韧的复合材料具有较好的力学性能。3.随着氧化锆含量的增加氟硅云母玻璃陶瓷力学性能逐渐增强。纳米氧化锆含量为30%时,具有较好的增强补韧效果。更多还原

【Abstract】 Fluorosilicic mica glass ceramics has excellent machinability, and become all-ceramic restoration material suiting for dentistry CAD/CAM. However, the glass ceramics exhibits low strength and toughness which limit the application of the clinic. The studies of fluorosilicic mica glass-ceramics mainly aim at keeping its excellent properties, and simultaneously enhancing its fracture strength and toughness in order to hold the dependability in clinical use. Recently, ceramic composite toughed by zirconia has become a study hotspot. The key idea of this work is to enhance fracture strength and toughness of Fluorosilicic Mica Glass-ceramics by adding zirconia. The aim is to provide important laboratory reference for future study.Content and methods:1. The first part of this study (experimentⅠ) is to compare the melt cast method with the sintering method in order to choose the better method to prepare zirconia toughened fluorosilicic mica glass-ceramic composites. Mechanical properties of zirconia toughened fluorosilicic mica glass ceramic composites were tested by three point bending strength and fracture toughness, and the microstructure and crystalline phase composition were analyzed by SEM and XRD apparatus.2. The purpose of experimentⅡis to determine which size of particle can more effectively improve the strength and toughness of the glass ceramics. This experiment is adopting the sintering method and adding different particle size (50nanometer and 10micron) of zirconia with the same content (25wt%) to fluorosilicic mica glass-ceramics, which is to investigate the influence of different particle size of zirconia on mechanical properties and microstructure of the glass-ceramics composites.3. ExperimentⅢis adding zirconia with the same particle size (50nanometer) but with different contents (5wt%, 10wt%, 20wt%, 30wt%) to fluorosilicic mica glass-ceramics and adopting the sintering method to prepare some samples. This experiment is to discuss the effect of different contents of nanometer zirconia toughened fluorosilicic mica glass-ceramics on the mechanical properties of the composites.Results:1. Zirconia toughened fluorosilicic mica glass-ceramics composite which prepared by the melt cast method and the sintering method have higher flexural strength and fracture toughness than that without zirconia. Composites which prepared by the sintering method showed much higher flexural strength and fracture toughness, which were134.4±10.2Mpa and 1.88±0.16MPa·m1/2 respectively. Composites which prepared by the melt cast were 128.5±12.1MPa and 1.62±0.06MPa·m1/2.2. Fluorosilicic mica glass-ceramics composites with nana-size powder of zirconia showed much higher flexural strength and fracture toughness, which were 220.8±9.30Mpa and 2.54±0.10 MPa·m1/2 respectively. There have significant difference between nana-size zirconia and micro-size zirconia toughened fluorosilicic mica glass-ceramics composite which prepared by sintering method in the flexural strength and fracture toughness(P<0.05).3. The flexural strength and fracture toughness of glass-ceramics with 30wt% ZrO2 which did not influence the crystallization process were 224.3±10.3MPa and 2.80±0.13MPa·m1/2 respectively. The flexural strength and fracture toughness with 5wt% and 10wt% nana-size zirconia toughened fluorosilicic mica glass-ceramics had no significant(P>0.05).Conclusions:1. The flexural strength and fracture toughness of zirconia toughened fluorosilicic mica glass-ceramics composite prepared by sintering method were much higher than those prepared by the melt cast method.2. Fluorosilicic mica glass-ceramics composites prepared by sintering method with the same content but different particle size of zirconia shows that the composite with nano-size powder of zirconia has higher flexural strength and fracture toughness than that with micro-size powder of zirconia.3. The mechanical property of fluorosilicic mica glass-ceramics composites is higher and higher with the increase of the zirconia content. The flexural strength and fracture toughness of glass-ceramics with 30 wt% nano-size of zirconia was reinforced significantly.更多还原