Effect of the addition of mullite–zirconia to the thermal shock behavior of zircon materials
Effect of the addition of mullite–zirconia to the thermal shock behavior of zircon materials
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DOI：
10.1016/j.msea.2008.08.036
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发表时间：
2008-12
期刊：
影响因子：
6.4
通讯作者：
N. Rendtorff;L. Garrido;E. Aglietti
中科院分区：
文献类型：
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作者：
N. Rendtorff;L. Garrido;E. Aglietti
陶瓷和耐火材料在使用过程中由于连续的加热冷却循环而受到局部温度和大气梯度的影响。这些情况产生热应力，其对限定耐火材料的潜在用途的材料造成一定程度的损坏。第二相的加入对提高致密陶瓷的抗热震性（TSR）的有利作用已被证实。然而，必须控制添加量，因为它会过度影响致密化和微观结构。本工作的目的是研究纯锆英石陶瓷材料的TSR，并量化莫来石-氧化锆（MZ）颗粒在15和45 wt.%之间的范围内添加的影响。对粉浆铸造棱柱形棒材进行了冷水淬火试验，以研究其热应力反应。对于热冲击测试，施加200 ° C和1200°C之间的温差（ΔT）。动态弹性模量（E）作为淬火试验的温差的函数，通过脉冲激励技术进行评估。E模量的降低也与热循环次数相关。材料的特点是密度测量和机械性能。采用XRD和Rietveld方法测定了样品的晶相组成。最后，用扫描电镜观察了材料的微观结构。对于所研究的所有复合材料，在超过400°C的ΔT下观察到E模量的显著变化。
Ceramics and refractories are subjected to local temperature and atmosphere gradients due to the successive application of heating cooling cycles, during service. These situations originate thermal stresses that cause certain degree of damage to the material defining the potential usage of the refractory. The favorable effect of the addition of a second phase for improving the thermal shock resistance (TSR) of dense ceramics have been proved previously. However the addition must be controlled because it can excessively affect the densification and microstructure. The objective of this work is to study the TSR of pure zircon ceramic materials and to quantify the influence of the addition of mullite–zirconia (MZ) grains in a range between 15 and 45wt.%. Cool water quenching test was carried out on slip cast prismatic bars in order to study the TSR. For the thermal shock tests temperatures differences (ΔT) between 200 and 1200°C were applied. The elastic dynamic modulus (E) was evaluated by the impulse excitation technique as a function of the temperature difference of the quenching test. The decrease in the E modulus was also correlated with the number of thermal cycles. The materials were characterized by density measurements and mechanical properties. The XRD and Rietveld method were employed for determining the crystalline phase composition. Finally, the microstructure of the materials was examined by SEM. Significant changes in the E modulus were observed for ΔT over 400°C for all composites studied.