酸洗粉煤灰烧结莫来石陶瓷及其力学性能  

Preparation of mullite ceramic by sintering of picked coal fly ash and its mechanical properties

作　　者：耿欣辉 卢金山[1] 李映德 GENG Xin-hui;LU Jin-shan;LI Ying-de(School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《材料热处理学报》2020年第2期147-152,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51562028);南昌航空大学研究生创新基金(YC2016024)。

摘　　要：以酸洗粉煤灰为原料,铝溶胶为铝源,烧结制备了莫来石陶瓷。利用X射线衍射和场发射扫描电镜等分析了莫来石陶瓷的晶体结构与微观形貌,研究了烧结温度和铝溶胶添加量对莫来石陶瓷的烧结行为、析晶过程以及力学性能的影响。结果表明:随着烧结温度升高,陶瓷体积密度、莫来石含量以及抗弯强度先增大后减小;随着铝溶胶添加量增大,陶瓷体积密度和莫来石含量持续增大,但抗弯强度和维氏硬度先增大后减小。酸洗粉煤灰中添加17.7%铝溶胶,1200℃烧结时莫来石陶瓷综合性能最佳,体积密度为2.67 g/cm^3,结晶度和莫来石含量分别为83.4%和50.2%,陶瓷抗弯强度和维氏硬度分别达到137.6 MPa和7.97 GPa。The mullite ceramic was prepared by using the pickled coal fly ash as the raw material and the boehmite as an aluminum source. The crystal structure and micro-morphology of the mullite ceramic were analyzed by means of X-ray diffraction and field emission scanning electron microscopy. The influence of the sintering temperature and the addition of the boehmite on sintering behavior, crystallization process and mechanical properties of the mullite ceramic was studied. The results show that, with the increase of the sintering temperature, the bulk density, the mullite content and the flexural strength of the mullite ceramic increase first and then decrease, and with the increase of the addition of the boehmite, the bulk density and the mullite content of the mullite ceramic increase continuously, but the flexural strength and the Vickers hardness increase first and then decrease. With the addition of 17.7% boehmite in the pickled coal fly ash, the comprehensive performance of the mullite ceramic sintered at 1200 ℃ is the best, the bulk density is 2.67 g/cm^3, the crystallinity and the mullite content are 83.4% and 50.2%, respectively, and the flexural strength and the Vickers hardness of the mullite ceramic reach 137.6 MPa and 7.97 GPa, respectively.

关 键 词：酸洗粉煤灰 铝溶胶 莫来石陶瓷 烧结行为 析晶过程 力学性能 

分 类 号：TB321[一般工业技术—材料科学与工程]