高炉冶金矿渣特性及其在ZTA陶瓷烧结中的作用

高炉渣是由炼铁高炉产生的一种工业废渣，其中含有CaO、Al₂O₃、SiO₂等硅酸盐成分和少量Fe₂O₃、TiO₂、ZrO₂等析晶形核剂。高炉渣在855℃热处理1 h，可形核析出1 μm左右的Ca₂Al₂SiO₇微晶，这表明高炉渣具有较高的析晶活性。向ZTA中添加质量分数为4%的高炉渣，1 550℃烧结30 min，低温下ZTA陶瓷的力学性能明显提升，抗弯强度和断裂韧性分别为650 MPa和6.03 MPa·m1/2，比相同温度下未添加高炉渣时分别提高了15%和14.2%，烧结温度降低了50℃以上。颗粒细化的高炉渣掺入ZTA陶瓷基体，烧结过程中高炉渣产生的液相促进了Al₂O₃棒晶的生长，受力过程中棒晶的拔出和裂纹的偏转有利于ZTA陶瓷力学性能的提升；高炉渣在高温下的析晶增强了ZTA陶瓷的晶界强度，进一步提高了材料的力学性能。 

Characteristics of Blast Furnace Slag and Its Role in ZTA Ceramics Sintering

Blast furnace slag is an industrial waste slag produced by ironmaking blast furnace, which contains silicate components such as CaO, Al₂O₃, SiO₂ and a small amount of crystallization nucleating agents such as Fe₂O₃, TiO₂, ZrO₂. After it was heat treated at 855 ℃ for 1 h, the crystal phase of Ca₂Al₂SiO₇ about 1μm could be nucleated and crystallized, which indicates that blast furnace slag has high crystallization activity. Adding 4% of blast furnace slag to ZTA, the mechanical properties of ZTA ceramics are significantly improved at low temperatures after sintered at 1 550 ℃ for 30 min. Flexural strength and fracture toughness are 650 MPa and 6.03 MPa·m1/2, respectively. There are 15% and 14.2% higher than that at the same sintering temperature without addition of blast furnae slag, and the sintering temperature is reduced by more than 50 ℃. The grain-refining furnace slag incorporated ZTA ceramic matrix, the liquid phase produces by blast furnace slag during the sintering process, which promotes the growth of Al₂O₃ rod crystal, the rod crystal extraction and crack deflection during the process of stress are conducive to the improvement of the mechanical properties of ZTA ceramics. The crystallization of blast furnace slag at high temperature enhances the grain boundary strength of ZTA ceramics and further improves the mechanical properties of the materials.