【作者】 宋文植；

【导师】 孙宏晨； 杨海滨；

【作者基本信息】 吉林大学 ， 口腔临床医学， 2004， 博士

【摘要】 陶瓷材料因其优异的性能被誉为“未来的材料”，在口腔修复领域，陶瓷材料以其极佳的生物相容性、良好的耐磨、耐腐蚀性和类似天然牙的美学性能成为修复材料的首选。自上世纪六十年代人们解决了金瓷匹配问题后，以金属底层冠增强的金属熔附烤瓷牙（PFM）成为口腔临床最为常用的固定修复方式，但金属底层的存在使金属烤瓷牙存在着难以克服的缺点，例如：金属离子的析出有潜在的致敏性，析出的金属离子可导致龈缘灰线影响美观，遮色层的存在阻止了光线透过使人工牙缺乏天然牙活力等。因此能够以高强度陶瓷材料取代底层金属冠，以达到最佳美学效果和生物相容性的全瓷修复已成为近年的研究热点和口腔修复的发展方向，并相继出现了IPS Impress热压铸陶瓷、In-Ceram系列粉浆涂塑渗透铝瓷等全瓷材料，近年又与先进的计算机辅助设计/计算机辅助制作（CAD/CAM）技术相结合研制出可机械加工的In-Ceram多孔铝瓷和Procera All Ceram高铝瓷预成瓷块，大大推进了全瓷修复体在临床的应用。但由于陶瓷材料的化学键大都为离子键和共价键，键结合牢固并有明显的方向性，室温下几乎不能产生滑移或位错运动，这种脆性本质限制了陶瓷材料的实际应用，克服其脆性、提高其韧性一直是材料学家们努力要解决的问题。 <WP=93>传统的陶瓷增韧方法有相变增韧、纤维增韧、晶须及颗粒韧化等，其中最为引人注目的材料之一是氧化锆相变增韧陶瓷，由于在应力作用下诱发四方相向单斜相的马氏体相变而使其断裂韧性大大提高，成为室温下韧性最好的陶瓷材料，故有“陶瓷钢”的美誉，而且其粉体还可以作为第二相颗粒填加到其它陶瓷基体中起到相变增韧作用。近年来氧化锆陶瓷优良的力学性能也引起了口腔医学家们的关注，成为引人注目的新型牙科材料。除了传统的增韧方法，近年来纳米科技的发展使新材料、新技术不断涌现，纳米陶瓷被认为是解决陶瓷脆性的战略途径。当前纳米氧化锆及纳米氧化锆复合陶瓷已成为材料学界的研究热点，因此本实验拟将纳米材料技术与口腔材料研究相结合，并将先进的放电等离子烧结技术(SPS)引入口腔材料研究，以期研制出高强度、高韧性，能满足口腔修复材料需求的纳米氧化锆复合陶瓷，并探讨其增强补韧机制，为应用新技术、新方法研制新型牙科陶瓷材料作出有益探索。本实验具体内容包括：(1) 超声波作用下共沉淀法制备纳米ZrO2　(3Y)粉体制备出粒度分布均匀、烧结性能良好的纳米粉体是得到较好力学性能的陶瓷材料的前提，本实验采用便于操作且反应条件易于控制的共沉淀法，以氧氯化锆、硝酸钇为原料，反向滴定制备钇稳定纳米氧化锆粉体，为防止反应过程中发生团聚，本实验采用低表面张力的乙醇为反应溶剂，分别在低频超声波作用和无超声波作用下进行反应，经透射电镜观察，超声波作用下制备的前驱体分散性好于非超声波作用下制备的前驱体，说明低频超声波有较好的反团聚作用。超声法制备的前驱体经600℃煅烧后得到粒径小、分散均匀的纳米ZrO2(3Y)粉体，经X射线衍射分析主要为四方相氧化锆，并通过谢乐公式计算晶粒平均粒径为D101 =15.58nm。 <WP=94>(2) 超声波作用下化学沉淀法制备纳米(-Al2O3粉体以硝酸铝为原料，乙醇为反应溶剂，低频超声波作用下制备纳米(-Al2O3粉体，经测试证明，前驱体经1200℃煅烧后，得到近似球形的分散性较好的纳米(-Al2O3粉体，晶粒平均粒径为D202=31.44nm。(3) 纳米氧化锆复合陶瓷的制备①填加不同比例纳米氧化锆粉体的纳米复合陶瓷 将体积比为3%、5%、10%、15%、20%、30%的纳米ZrO2(3Y)粉体分别加入微米级氧化锆造粒粉中，球磨混匀，250Mpa干压成型，对烧结后试样进行线收缩率、密度、表观气孔率、力学性能测试及XRD相结构分析和SEM观察，结果表明，加入3%、5%、10% ZrO2(3Y)纳米粉组三点弯曲强度和断裂韧性值与对照组（纯造粒粉陶瓷）相比均有统计学意义，其中添加10%纳米粉的陶瓷试样力学性能最好，其三点弯曲和断裂韧性值分别为673.17±47.19Mpa和9.01±0.82Mpa·m1/2；可以满足口腔修复材料要求；添加纳米粉超过20%时，力学性能反而下降，添加纳米粉达30 %时，试样力学性能已明显低于对照组。②填加不同比例纳米(-Al2O3粉体的纳米Al2O3/ZrO2（3Y）复合陶瓷将体积比分别为3% 、5 %、10 %、15 %、20 %、30 %的纳米( - Al2O3粉体加入微米级氧化锆造粒粉中，球磨混匀，250Mpa干压成型，烧结后测试各组试样性能指标。结果表明，加入3%、5%(-Al2O3纳米粉组三点弯曲强度和断裂韧性值与对照组相比有统计学意义，其中添加5%纳米粉的陶瓷试样力学性能最好，其三点弯曲和断裂韧性值分别为659.17±46.54 Mpa和8.55±0.89 Mpa·m1/2，可以满足口腔修复材料要求；添加纳米粉超过20 %时，试样力学性能反而下降。 <WP=95>(4) 放电等离子快速烧结牙科纳米ZrO2陶瓷及纳米Al2O3 - ZrO2（3Y）复合陶瓷初探分别将纯纳米ZrO2粉体和以50 %比例混匀的纳米Al2O3 - ZrO2（3Y）复合粉体，应用先进的SPS技术快速烧结，得到的纯纳米ZrO2陶瓷试样开裂，X射线衍射分析表明试样中基本为m - ZrO2，说明其中的稳定剂Y2O3被模具中的碳还原而失去作用；纳米Al2O3 - ZrO2（3Y）复合陶瓷试样未开裂更多还原

【Abstract】 Ceramic is praised as “future material” for its unique properties, especially is considered to be the best choice as prosthetics materials because of its excellent biocompatibility、corrosion and abrasive resistance 、nature aesthetic traits. Now the porcelain-fused-to-metal ( PFM ) restoration has become the most commonly clinical restorative way since the matching problem between ceram and metal material was resolved in the 60s’last century.But the metal substructures exist many shortcomings such as the poor biocompatibility and poor aesthetics caused by the deposition of metal ions, the absence of nature vigour because of the poor transparence,et al. To overcome the disadvantages, all - ceram restoration which substitute the ceramic core crown for metal substructure has become the developping trend and researching focus. But the inherent brittleness and lower strength limit the all-ceram materials’application.researchers are attemping to overcome the brittleness 、enhance its fracture strength and toughness. With the developping of nanotechnology,nano-ceramic <WP=98>was considered to be the statistic way to resolve ceramic’s brittleness. So The key idea in this study was to bring nano-materials into dental material research, combine the toughening effect of phase transformation of Zirconia and nano-particles to develop new type of Zirconia nano-ceramic composites,which have better mechanical properties and can meet the demand of prosthetics material.In addition,we try to use advanced S P S technology to develop Zirconia nano-ceramic composites for dental application,and get some benefit results. The study including:1、The preparation of ZrO2 (3Y ) nanopowder by co-precipitation under ultra-sonic radiation.In this experiment we prepared ZrO2(3Y) nanopowder which average granule diameter was D101 =15.58nm using ZrOCl 2·8H 2O and Y2 O3 as raw materials,ethanol which had low surface tension as reaction solvent under low-frequent ultro-sonic radiation; 2、The preparation of Al2O3 nanopowder by chemical-precipitation under ultra-sonic radiation.In this experiment we preparedα- Al2O3 nanopowder which average granule diameter was D202=31.44nm under the same reactive conditions above.3、The preparation of Zirconia nano-ceramic composites; Different volume percentage of ZrO2 ( 3Y ) and α- Al2O3 nanopowder was added into micronmetric ZrO2 ( 3Y ) granulated powder respectively , different test ways, including X-ray diffraction (XRD),scanning electron microscopy (SEM) ,and mechanical tests were used in this study ;4、The preparation of Zirconia nano-ceramic and nano-ceramic composites by Spark plasma sintering (SPS) method. In this experiment we prepared ZrO2(3Y) nano-ceramic and Al2O3- ZrO2(3Y) nano-ceramic <WP=99>composites by advanced SPS technology and tested their properties respectively.The results showed:1、We can get uniform dispersed nano-sized ZrO2 ( 3Y )andα- Al2O3 powder by chemical precipitation method under ultrasonic radiation;2、Low frequency of ultrasonic could have effective anti-agglemeration action during the preparation of nano-powder;3、Nano-powder as the additive has a well proportion,the samples mingled with 10vol % ZrO2 ( 3Y ) nano-powder and 5vol %α- Al2O3 nano-powder has the best mechanical properties in their group respectively ,the strength of three point bend and fracture toughness of the nano-ceramic composites mingled with 10vol % ZrO2 ( 3Y ) and 5vol%α- Al2O3 nano-powder were 673.17±47.19Mpa and 9.01±0.82Mpa·m1/2、659.17±46.54 Mpa and 8.55±0.89 Mpa·m1/2 respectively. Too much nano-powder worsened the mechanical properties on the contrary;4、The Zirconia ceramic sintered by SPS needed subsequence oxidation because of the deoxidation of the stabilizer ;5、Al2O3- ZrO2 (3Y) nano-ceramic composites undergone subsequence oxidation had better mechanical properties which could satisfied the demands to be dental ceramic material, the strength of three point bend and fracture toughness of the samples were633.50±51.70 Mpa and 8.25?更多还原