ZrO_2对刚玉–尖晶石浇注料抗热震性能的影响

Effect of Zirconia on Thermal Shock Resistance of Corundum–Spinel Castables

为制备具有优良抗热震性能的刚玉–尖晶石浇注料,在浇注料中加入0～9%(质量分数,下同)的氧化锆,通过测试弹性模量和残余抗折强度研究了氧化锆对刚玉–尖晶石浇注料抗热震性能的影响。利用X射线衍射和扫描电子显微镜分析了刚玉–尖晶石–氧化锆浇注料抗热震性能的影响机制。结果表明:刚玉–尖晶石浇注料的弹性模量随氧化锆加入量增加逐渐降低,由129 GPa(未加ZrO2)降至93.6 GPa(加入9%ZrO2),而残余抗折强度随氧化锆加入量增加而升高,经5次1 100℃水冷热震循环后,残余抗折强度保持率由59%(未加ZrO2)提高到83%(加入9%ZrO2)。提高刚玉–尖晶石浇注料抗热震性能的机制为微裂纹增韧、ZrO2粒子弥散增强和钉扎效应等多重因素共同作用。

In order to preparing good thermal shock resistance corundum–spinel castables,zirconia of 0–9%（in mass,the same below） was added.Effect of zirconia on materials’ thermal shock resistance was investigated by measurement of elasticity modulus and re-sidual hot modulus of rupture（HMOR） ratio.The mechanism which influence on the thermal shock resistance of the materials is ana-lyzed by means of X–ray diffraction and scanning electron microscope.The results indicate that the more zirconia is added,the lower elasticity modulus and the higher residual HMOR ratio of castables can be obtained.With the increase of content of ZrO2 from 0 to 9%,elasticity modulus of corundum–spinel castables decreases from 129 GPa to 93.6 GPa.Residual HMOR ratio of corundum–spinel casta-bles after five times thermal shock（from 1 100 ℃ to cold water） increases to 83% when 9% ZrO2 is added,while the ratio is only 59% when no ZrO2 is added.It shows that good thermal shock resistance of corundum–spinel castables is correlated to the combined factors such as micro-crack toughening,ZrO2 particles dispersion reinforcing and pinning effect,etc.