MgO-ZrO2砖的高温抗折性能和抗热震性能的研究

为了研究高温抗折和抗热震性能优良的RH炉用镁锆耐火材料,通过正交试验研究了配料方法和颗粒级配、原材料种类、烧结温度、氧化锆含量等因素对镁锆砖性能的影响.结果表明：镶嵌在基质中的氧化锆稳定了方镁石,增强了材料的强度;氧化锆相变导致微裂纹能吸收断裂能,使镁锆材料的抗热震性能得到改善,特别是添加单斜氧化锆的镁锆砖相变增韧作用更显著;而添加锆英石时由于生成了低熔点硅酸盐使材料致密,对镁锆砖的高温抗折强度和抗热震性能均不利,制备RH炉用镁锆不宜采用锆英石原料.

Investigation on hot rupture and thermal shock resistance of magnesia-zirconia brick

In order to study hot modulus of rupture and thermal shock resistance of MgO-ZrO2 refractory used for RH Degasser,effects of several factors including optimization methods of raw materials,grain size composition,zirconia content and sintering temperature on the property of magnesia-zirconia brick were studied by orthogonal test.The results indicates that zirconia embedded in matrix could stabilize periclase and strengthen the materials;micro-cracks caused by phase transformation of zirconia could absorb fracture energy and enhance thermal shock performance of materials,especially when monocline zirconia was added,the reinforcing and toughening effects of zirconia would be even more pronounced;while zircon added into refractory would lead to the direct-bond of periclase and zirconia and made the material densified because of the generation of silicate liquid phase during the sintering process,which would go against with the improvement of hot modulus of rupture and thermal shock resistance of magnesia-zirconia brick.