MgO-MnO_2-TiO_2-SiO_2烧结助剂中SiO_2的量对低温烧结氧化铝陶瓷材料性能的影响

The Effect of SiO_2 Amount in MgO-MnO_2-TiO_2-SiO_2 on Properties of Alumina Ceramic Sintered by Low-temperature

本文采用MgO-MnO2-TiO2-SiO2复相添加剂作为氧化铝陶瓷的烧结助剂,采用注浆成型工艺,研究了改变添加剂SiO2的量对1400℃和1450℃烧结的Al2O3陶瓷材料性能的影响。运用三点抗弯电子试验机、XRD、SEM分析了低温烧结Al2O3基陶瓷材料的力学性能和断口形貌,讨论了低温烧结Al2O3基陶瓷的烧结机理和性能。结果表明:在1450℃烧结,当不加SiO2时,弯曲强度为194MPa;当加入0.5%(质量百分含量,下同)SiO2时,烧结Al2O3基陶瓷材料的力学性能最佳,弯曲强度为σ=299MPa;SiO2量增加到1%时,σ=293MPa;SiO2加入量在3%时,σ=249MPa。SiO2的加入量从0.5%到3%对氧化铝的强度都有明显的提高,说明加入SiO2对氧化铝陶瓷的烧结是非常有利的,但随着SiO2加入量的不断加大氧化铝陶瓷力学性能有下降的趋势。

In this paper, MgO-MnO2-TiO2-SiO2 composite additives was introduced into alumina ceramics as sintering agent. The alumina ceramics were made by slip casting method then sintered at 1400℃ and 1450℃ respectively. The effects of the amount of the SiO2 additive on the properties of the alumina ceramics were studied. The strength, the phases, and the mierostructure of the low-temperature-sintered alumina ceramics were analyzed by three point bending, electronic testing machine, XRD and SEM methods. Meanwhile, the sintering mechanism and some properties were also discussed. The results show that the strength of the material without SiO2 additive is 194 MPa; the alumina ceramics show the best mechanical performance when the amount of SiO2 is 0.5 % , in this case, the strength reached 299 MPa when sintered in air at 1450 ℃ for 1 h; but at this sintefing temperature, the amount of SiO2 is 1% , the strength of the material is 293 MPa ; and the amount of SiO2 is 3%, the strength of the material is 249 MPa after sintered in air for 1 h. The addition of SiO2 from 0.5% to 3% on the strength of aluminum has increased significantly, adding that the amount of SiO2 on the sintering of alumina ceramic is very favorable, but with the addition of SiO2 increasing the mechanical properties of alumina ceramic tends to decrease.