高强度莫来石陶瓷微晶薄板的研究

Research on High Strength Mullite Based Micro-crystalline Ceramics Thin Tiles

为了降低莫来石微晶陶瓷的合成成本,用粉煤灰、铝矾土与叶腊石等为原料,以氟化铝(AlF3)为矿化剂,在相对较低的温度下合成了莫来石质的陶瓷微晶薄板。采用综合热分析仪(TG-DSC)、X射线衍射仪(XRD)和扫描电子显微镜(SEM)对样品进行表征。结果表明:随煅烧温度的升高,试样的气孔率和吸水率逐渐降低,试样中莫来石晶相含量、弯曲强度、密度逐渐增加。当煅烧温度为1200℃时,试样得弯曲强度达到96MPa。AlF3矿化剂的加入有利于促进莫来石的析晶和微晶板材的烧结,随AlF3矿化剂加入量的逐渐增加,试样的弯曲强度呈现先增加后降低的趋势,其适合的加入量为4.0wt%。

In order to reduce the cost of the mullite based micro-crystalline ceramics, fly ash, bauxite and pyrophyllite were used as raw materials. The as-prepared samples were characterized by thermogravimetry-differential scanning calorimeter （ TG-DSC）, X-ray diffraction （XRD） and scanning electron microscope （SEM） analyses. The results show that the porosity and water absorption of the ceramics decrease as the sintering temperature increasing. Correspondingly, the mullite content, bending strength and density of the samples are obviously increases as the fired temperature increasing. When the sintering temperature reaches 1200℃, the bending strength of the ceramics arrives to the maximum value 96 MPa. The introduction of AlF3 is helpful for the crystallization of mullite and sintering of the ceramics. With the increase of the AlF3 content, the bending strength of the samples firstly increases and then decreases. The proper addition content of AlF3 is demonstrated as 4.0 wt%.