Abstract

MgO-Al₂O₃-SiO₂ composite ceramics are widely used in high-temperature filter materials, refractories, catalyst carrier materials and insulating materials because of their low coefficient of thermal expansion, good high-temperature stability and mechanical properties. In the process of preparing MgO-Al₂O₃-SiO₂ composite ceramics, it is more important to select a suitable mineralizer in order to effectively reduce the sintering temperature of MgO-Al₂O₃-SiO₂ composite ceramics and improve the properties of MgO-Al₂O₃-SiO₂ composite ceramics. In this experiment, 97 grade fused magnesia, Al₂O₃ powder and ferrosilicon ash powder were used as main raw materials. Meanwhile, Cr₂O₃ powder, ZrO₂ powder and TiO₂ powder were selected as mineralizers. MgO-Al₂O₃-SiO₂ composite ceramics were prepared by the semi-dry pressing method. The effects of different mineralizers on the sintering properties of MgO-Al₂O₃-SiO₂ composite ceramics were studied. The experimental results show that the addition of Cr₂O₃ powder cannot promote the sintering of MgO-Al₂O₃-SiO₂ composite ceramics and the addition of TiO₂ powder and TiO₂ powder can promote the sintering of MgO-Al₂O₃-SiO₂ composite ceramics. Moreover, the sintering performance of MgO-Al₂O₃-SiO₂ composite ceramics is better than that of MgO-Al₂O₃-SiO₂ powder. When the addition of ZrO₂ powder is 4%, it can promote the formation of periclase phase, refine grains and play a toughening effect, and the bending strength of MgO-Al₂O₃-SiO₂ composite ceramics reaches the maximum value of 19.3 MPa.

摘要

MgO-Al ₂ O ₃ -SiO ₂复合陶瓷由于其热膨胀系数低、高温稳定性好和机械性能好，被广泛应用于高温过滤材料、耐火材料、催化剂载体材料和绝缘材料。在制备MgO-Al ₂ O ₃ -SiO ₂复合陶瓷的过程中，选择合适的矿化剂才能有效降低MgO-Al ₂ O ₃ -SiO ₂复合陶瓷的烧结温度，提高其性能。 MgO-Al ₂ O ₃ -SiO ₂复合陶瓷。本实验以97级电熔镁砂、Al ₂ O ₃粉体和硅铁灰粉为主要原料。同时，选择Cr ₂ O ₃粉体、ZrO ₂粉体和TiO ₂粉体作为矿化剂。采用半干压法制备MgO-Al ₂ O ₃ -SiO ₂复合陶瓷。研究了不同矿化剂对MgO-Al ₂ O ₃ -SiO ₂复合陶瓷烧结性能的影响。实验结果表明，Cr ₂ O _{3 的加入}粉体不能促进MgO-Al ₂ O ₃ -SiO ₂复合陶瓷的烧结，TiO ₂粉体和TiO ₂粉体的加入可以促进MgO-Al ₂ O ₃ -SiO ₂复合陶瓷的烧结。此外，MgO-Al ₂ O ₃ -SiO ₂复合陶瓷的烧结性能优于MgO-Al ₂ O ₃ -SiO ₂粉体。当添加 ZrO ₂粉量为4%，可促进方镁石相的形成，细化晶粒，起到增韧作用，MgO-Al ₂ O ₃ -SiO ₂复合陶瓷的抗弯强度达到最大值19.3 MPa。