【作者】 彭超；

【导师】 徐晓虹；

【作者基本信息】 武汉理工大学 ， 材料加工， 2003， 硕士

【摘要】 本研究利用湖北钟祥出产的具有特殊结构的累托石矿物为主要粘土原料，添加滑石粉和工业氧化铝成功的合成了优质堇青石。本文查阅国内外大量的有关资料并进行了进行理论分析；通过测定样品的吸水率、气孔率、体积密度、抗折强度及热膨胀系数等对样品进行理化性能分析；采用XRD、SEM测试手段对样品的相组成和微观结构进行分析，最终确定了堇青石的合成工艺。在本研究中，还试图通过添加外加剂来降低堇青石的热膨胀系数。在查阅资料的基础上，实验中的添加剂选定为三氧化二钕、钛酸铝、锂辉石、锆英石、氧化铈、MgO₃—Al₂O₃—SiO₂—Z_rO₂系统中添加锂辉石、MgO₃—Al₂O₃—SiO₂系统中添加氧化锗。这些化合物添加剂对堇青石的多个性能都起到改善的作用，经过对添加方式的研究，发现生料中直接外加添加剂，不仅省却了一些工艺过程，同时也是改善性能的最佳方式。对添加外加剂后的堇青石样品的理化性能及相组成和微观结构进行了测试和分析。结果表明：利用累托石可以在1280℃保温2小时的条件下合成性能优异的堇青石陶瓷制品，堇青石的热膨胀系数为2.73×10^-6／℃，吸水率为8.17％、气孔率18.17％，体积密度达2.07g／cma，抗折强度为65.46Mpa：在生料中直接添加外加剂后，堇青石的热膨胀系数有比较大的降低幅度，添加氧化钕2.5％时，堇青石的热膨胀系数最低为2.59×10^-6／℃，添加钛酸铝15％时，堇青石的热膨胀系数最低为2.60×10^-6／℃，添加锂辉石6％时，堇青石的热膨胀系数最低为2.63×10^-6／℃，添加锆英石11％时，堇青石的热膨胀系数最低为2.51×10^-6／℃，添加氧化铈0.8％时，堇青石的热膨胀系数最低为2.61×10^-6／℃，MgO₃·Al₂O₃·xG_eO₂·（5-x）SiO₂中氧化锗1.5mol时，堇青石的热膨胀系数最低为2.55×10^-6／℃，并且理化性能也有相应的提高，吸水率、气孔率、体积密度、抗折强度都有明显的改善，从而证明外加剂的引入是一个很好的改善性能途径。更多还原

【Abstract】 Cordierite is a low expansion coefficient material of a wide range of application ,and this is the main purpose of this study. The study successfully synthesized a high-quality cordierite using a special ore material-rectoritex as the main clay raw material ,which was produced at Zhongxiang, Hubei province ,and talc powder and industrical Al2O3 as the additives.First.this study proceeded the theories analysis by referring to a large quantity of interrelated data ,both domestic and international;then made a array of analysis towards the chemical and physical performances of the samples by testing the water absorption,open porosity, bulk density, banding strength and thermal expansion coefficient ,etc;after these the study analysted the microstructure of the samples using XRD and SEM, finally the author established the synthesizing process of the cordierite. During the study we tried to lower the thermal expansion coefficient of cordierite by adding additives. On the basis of the data referred to, the additives as Nd2O3 , Al2TiO5 , Li2SiO3 ,ZiSiO3 , CeO are used in the study,while adding Li2SiO3 in MgO-Al2O3- SiO2 -ZrO2 system and GeO in MgO - Al2O3 - SiO2. As a result ,many performances of cordierite were improved by adding these compound additives.After the study towards the way that the additives be added in the materials ,we finally fixed that directly adding additions in the raw materials not only saved some synthesizing process, but also a best way to improve the properties . The chemical and physical properties, phase fabricates and microstructure of the samples that added additions were tested by the testing methods above. The results showed that the cordierite can be synthesized at a lower temperature (1280 ,2h) while using the rectorite as the main clay raw material, and the thermal expansion coefficient is 2.73×10-6 /℃, the water absorption is 8.17%, the porosity is 18.17%, the bulk density is 2.07 g/cm3,and the banding strength is 65.46Mpa; after adding additives, the thermal expansion coefficient ofcordierite had a large lowed range, that the lowest value is 2.59×10-6 / ℃ while adding Nd2O3 15%, 2.60×10-6/℃ while adding Al2TiO5 15%,2.63× 10-6 /℃ while adding Li2SiO3 6%, 2.51×10-6/℃ while adding ZiSiO3 18%, 2.61×10-6 /℃ while adding CeO 0.8%,2.55 ×10-6 /℃ when adding GeO2 1.5mol in MgO·Al2O3·xGeO·(5-x)SiO2 system,and the chemical and physical properties of the samples have homologously improved, as well as the water absorption, porosity, bulk density and banding strength. Then we can make a conclusion that adding additives is a good way to improve properties.更多还原