【摘要】 镁钙质耐火材料具有良好的耐高温性能和净化钢液能力,作为洁净钢、特殊钢冶炼用炉衬材料应用前景广阔。然而,该类材料难烧结、易水化和力学性能有待提升等问题亟待解决。本文制备了Y₂O₃/ZrO₂共掺杂MgO-CaO耐火材料,并与Y₂O₃、ZrO₂单掺杂材料进行了对比分析,研究了Y₂O₃/ZrO₂的引入对材料显微结构和性能的影响。结果表明,Y₂O₃单掺杂MgO-CaO耐火材料后,一部分固溶进入氧化钙晶格,而另一部分赋存于晶间,阻碍了材料烧结。协同引入少量ZrO₂后,材料的致密度提高,且常温抗折强度和抗水化性能明显改善。原位生成的CaZrO₃填充在材料孔隙中,提高了材料的烧结性能。然而,当引入过量的ZrO₂时,CaZrO₃生成量较多,产生明显体积膨胀导致材料显气孔率上升,力学性能和抗水化性能下降。更多还原

【Abstract】 MgO-CaO refractories have a broad application prospect as furnace lining materials for clean steel and special steel smelting due to their good high temperature resistance and ability to purify steel. However, these materials still have problems such as difficult sintering, easy hydration and mechanical properties need to be improved. In this work, Y₂O₃/ZrO₂co-doped MgO-CaO refractories were prepared by comparing with Y₂O₃ and ZrO₂ single-doped MgO-CaO refractories.The effect of Y₂O₃/Zr O₂ introduction on the microstructure and properties of materials was investigated. The results show that some Y₂O₃ dissolves into the Ca O lattice, while other Y₂O₃ locates at the intergranular region in the Y₂O₃ single-doped MgO-CaO materials. The intergranular Y₂O₃ hinders the sintering of the material. When a small amount of ZrO₂ is synergistically introduced, the density of the material increases, and the room temperature flexural strength and hydration resistance are improved. This is due to the in-situ generated Ca Zr O₃ filling in the voids, which is favourable to the sintering properties of the materials. However, when excessive ZrO₂is introduced, more Ca ZrO₃ generates in the materials, and the significant volume expansion leads to the increase of apparent porosity, leading to a decrease in the mechanical properties and hydration resistance of the materials.更多还原