Influence of in situ phase formation on properties of calcium zirconate refractories
Influence of in situ phase formation on properties of calcium zirconate refractories
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DOI：
10.1016/j.jeurceramsoc.2016.08.017
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发表时间：
2017
影响因子：
5.7
通讯作者：
S. Schafföner;J. Fruhstorfer;C. Faßauer;L. Freitag;C. Jahn;C. Aneziris
中科院分区：
文献类型：
--
作者：
S. Schafföner;J. Fruhstorfer;C. Faßauer;L. Freitag;C. Jahn;C. Aneziris
研究了锆酸钙耐火材料的化学、物理、机械和热机械性能。使用的电熔原料中含有少量残留的立方氧化锆，影响了CaZrO_3耐火材料的耐腐蚀性。为了调整化学计量比，加入了碳酸钙。此外，在不改变相组成的情况下，加入化学计量比的CaCO_3/单斜相ZrO_2以促进原位成孔。烧成后，只在粗粒集料中发现了立方氧化锆。CaCO3的加入由于化学计量比的调整，增加了显气孔率，降低了热膨胀系数。令人惊讶的是，较高的孔隙率并没有导致抗热震性的改善，这可以归因于向更大的孔尺寸转变。这可能会导致较低的裂纹密度，这通常与抗热震性降低有关。未来的工作将解决更小气孔的形成和实际条件下抗热震性的评估。
This study investigates chemical, physical, mechanical, and thermomechanical properties of calcium zirconate (CaZrO3) refractories. The applied fused raw material contained some residual cubic zirconia, which impairs the corrosion resistance of CaZrO3refractories. To adjust the stoichiometry, CaCO3was added. Furthermore, stoichiometric amounts of CaCO3/monoclinic ZrO2were added to promote an in situ pore formation without altering the phase composition. After firing cubic zirconia was only found in the coarse grained aggregates. CaCO3additions increased the apparent porosity and reduced the thermal expansion coefficient due to the stoichiometric adjustment. Surprisingly, a higher porosity did not result in an improved thermal shock resistance, which can be attributed to a shift to larger pore sizes. This might cause a lower crack density, which is usually associated with a reduced thermal shock resistance. Future work will address the formation of smaller pores and the evaluation of the thermal shock resistance under practical conditions.