球磨化学反应法制备TZP超细粉体研究

发布时间：2018-03-31 09:43

  本文选题：球磨化学反应法　切入点：3Y-ZrO_2　出处：《广东工业大学》2011年硕士论文

【摘要】：氧化锆陶瓷具有十分优异的物理、化学性能,不仅在科研领域已经成为研究热点,而且在工业生产中也得到了广泛的应用,是结构材料、耐火材料和电子材料的重要原料。其主要应用在：四方氧化锆多晶体陶瓷、氧化锆超塑性陶瓷、部分稳定氧化锆陶瓷、氧化锆生物陶瓷等方面。而3Y-ZrO2(摩尔分数为3%Y2O3(?)急定的四方相ZrO2陶瓷)作为四方氧化锆多晶体(TZP)陶瓷的一种,其硬度高,耐磨性、耐腐蚀性能好,常用于严酷环境和苛刻负载条件。因此,3Y-ZrO2的研究一直方兴未艾。制备氧化锆陶瓷粉体的传统方法有物理法和化学法两大类,包括喷雾热解法、液相法、气相法、固相法等。 本研究借助固相法固有的优势及特点,利用球磨化学反应法法制备3Y-ZrO2陶瓷粉体。借助TG-DTA分析前驱体的热分解过程,通过XRD、TEM、DLS、BET对所得产物进行了表征,并系统地探讨了工艺条件对最终产物的平均晶粒粒径、晶相含量、粒度分布及粉体形貌的影响,研究内容如下：(1)通过单因素实验,考察前驱体制备过程中各因素(如金属离子与草酸的摩尔比、球料质量比、球磨转速、球磨时间)对最终产物的影响(如平均晶粒粒度、晶相含量、晶体形貌等)；并采用正交试验对单因素结果进行优化,优化结果显示各因素对粉体的平均晶粒大小影响顺序为：金属离子与草酸的摩尔比球料质量比球磨速度。从节约原料和提高效率考虑,最佳工艺条件为：金属离子与草酸的摩尔比1：1.5,球料质量比为10：1,球磨时间为1h,球磨速度为200rpm。该工艺条件下所得3Y-ZrO2陶瓷粉体的平均晶粒粒径为14.0nm,形状比较规整,近似球型结构,粒度分布均匀,分散性较好。通过对前驱体进行TG-DTA分析,确定最佳煅烧工艺为：煅烧温度为650℃,煅烧时间为2h。随着煅烧温度的升高,煅烧时间的延长,所得产物的平均晶粒粒径增大,四方相氧化锆的含量逐渐减少。(2)在行星球磨制备3Y-ZrO2超细粉体的工艺基础上,利用搅拌球磨反应法进行放大实验,本次研究放大实验所制备的3Y-ZrO2超细粉体的表征结果显示该粉体粒度分布均匀、分散性良好,其平均晶粒粒径约为24.9nm,比表面积为32.4608 m2/g。粉体经配料球磨24小时后喷雾造粒,粉料成型性能好,表面手感光滑,松装密度小。烧结温度1530度,成瓷后颜色死白,无透感,不吸红,收缩偏大。分析原因在于原料中铁杂质的含量较高,前驱体的煅烧过程中,其煅烧工艺未严格控制。 (3)选择放大实验所得前驱体进行煅烧试验,结果表明,随着煅烧温度的升高,煅烧时间的延长,样品中的平均粒径增大,四方氧化锆的体积含量逐渐减少,单斜相氧化锆的体积含量逐渐增大。在前人的研究结果上,我们认为本研究理论解释更接近Garvie的观点,单斜氧化锆具有比四方氧化锆大的表面能。而在一定的温度和压力下,随着氧化锆粒径的长大,单斜相与四方相结构之间的表面能差别逐渐减少。
[Abstract]:Zirconia ceramics have excellent physical and chemical properties, not only in the research field has become a research hotspot, but also in industrial production has been widely used as structural materials, Important materials for refractories and electronic materials. Their main applications are: tetragonal zirconia polycrystalline ceramics, zirconia superplastic ceramics, partially stabilized zirconia ceramics, zirconia bioceramics, etc. ) as a kind of tetragonal zirconia polycrystalline ZrO2 ceramics, it has high hardness, wear resistance and corrosion resistance. The traditional methods of preparing zirconia ceramic powders include physical and chemical methods, including spray pyrolysis, liquid phase method, gas phase method, solid phase method and so on. In this study, 3Y-ZrO2 ceramic powders were prepared by ball milling chemical reaction method with the help of the inherent advantages and characteristics of solid state method. The thermal decomposition process of the precursor was analyzed by TG-DTA, and the obtained products were characterized by XRDX Tem Tem DLSX BET. The effects of processing conditions on the average grain size, crystal phase content, particle size distribution and powder morphology of the final product were systematically discussed. The effects of various factors (such as molar ratio of metal ions to oxalic acid, mass ratio of ball to material, ball milling speed, milling time) on the final product (such as average grain size, crystal phase content) were investigated. The single factor results were optimized by orthogonal test. The optimized results show that the order of the influence of various factors on the average grain size of the powder is as follows: the molar ratio of metal ions to oxalic acid is the rate of ball milling. The optimum technological conditions are as follows: the molar ratio of metal ion to oxalic acid is 1: 1.5, the mass ratio of ball to material is 10: 1, the milling time is 1 h, and the milling speed is 200rpm.The average grain size of 3Y-ZrO2 ceramic powder is 14.0 nm, the shape is relatively regular, and the shape is similar to the spherical structure. The particle size distribution is uniform and the dispersity is good. Through the TG-DTA analysis of the precursor, the optimum calcination process is determined as follows: the calcination temperature is 650 鈩，

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