利用锰渣合成堇青石/钙长石复相陶瓷及其抗热震性能研究

以锰渣、滑石、工业氧化铝、石英为原料,在1 140~1 240℃温度内采用固相烧结法制备了堇青石、钙长石陶瓷。利用X射线衍射仪和扫描电子显微镜研究了产物的物相组成和显微结构,分析了样品的抗热震性能及其机制。结果表明,钙长石相在1 160~1 240℃内均能烧成,堇青石晶体则在1 210℃及以上方能合成,烧结温度超过1 220℃则会出现过烧现象。热震测试表明,随热循环次数增加,1 210℃温度下烧成的堇青石/钙长石复相陶瓷的强度先降低,后逐渐回升。经30次热循环后材料的抗折强度高达58.16 MPa,超过热震前的56.98 MPa,增加率达2.07%。热震类似于退火,材料优良的抗热震性能可归因于淬火强化效应。

Synthesis and thermal shock resistance of cordierite/anorthite multiphased ceramics using manganese residue

Using manganese residue, talc, industrial alumina and quartz as the raw material, the cordierite and anorthite ceramics were prepared at 1 140-1 240 ℃ by the solid phase sintering method. The phase compositions and microstructures of products were studied by X-ray diffractometer and scanning electron microscope, and thus the thermal shock resistance and its mechanism of sintered samples were analyzed. It is found that the anorthite phase could be synthesized at 1 160-1 240 ℃, but the cordierite phase could be synthesized only when the sintering temperature reached 1 210 ℃ and above, and the "overburning" would occur once the temperature exceeding 1 220 ℃. The thermal shock testing shows that, with the thermal shock cycles rising, the strength of cordierite/anorthite multiphased ceramics synthesized at 1 210 ℃ decreased firstly, and then gradually rose again. After 30 thermal cycles, the bending strength of composite unexpectedly reached 58.16 MPa with 2.07% increase rate comparing to 56.98 MPa bending strength before thermal shock. Thermal shock was similar to annealing, and the excellent thermal shock resistance of composite could be attributed to the effect of quenching strengthening.