掺杂La_(2)O_(3)对制备堇青石结合碳化硅陶瓷耐火材料加热炉衬里的制备改性研究

Research on Preparation and Modification of Cordierite Bonded Silicon Carbide Ceramics Doped with La_(2)O_(3)for Reheating Furnace Refractory Slab

随着当今世界产业多元化发展,以消耗能源为主要动力的电力、冶金、汽车、煤炭等行业面临着严峻的环境污染危机。碳化硅多孔陶瓷由于具有优异的高温力学性能,良好的耐腐蚀性,较强的抗热震性等特性,日益成为工业生产中高温气体净化的高效核心部件。堇青石作为硅酸盐体系中稳定的化合物,利用其高温稳定性,将其与碳化硅制成复合陶瓷基材,有效地提高加热炉耐火材料的高温机械强度。本文系统地探究了掺杂La_(2)O_(3)对于堇青石结合碳化硅多孔陶瓷的改性影响。实验得出:La_(2)O_(3)作为一种密堆六方的镧系稀土元素,能有效地抑制方石英的生成,促进堇青石相的低温合成,当掺杂0.6wt%La_(2)O_(3)时,其抗弯强度和气孔率均达到最优值,分别为62.26MPa、31.40%。但过多的添加La_(2)O_(3)助剂,随着温度的升高,其产生过多的熔融液相会使得陶瓷材料的气孔率和强度骤降。

With the industrial development of the world economy,using energy consumption as the main driving force of the electric power,metallurgy,chemical,coal and other industries are facing severe environmental pollution crisis.Due to the porous silicon carbide ceramics having excellent high-temperature mechanical properties,good corrosion resistance,thermal shock resistance and other strong features,it is increasingly becoming the removal efficiency core components for high temperature gas dust in industrial production.Cordierite as the stable compound in the Al_(2)O_(3)-MgO-SiO_(2)system,for its low coefficient of thermal expansion,high thermal stability,combined with a porous silicon carbide to produce composite ceramic substrate can not only improve the overall thermal shock resistance,while can reduce the sintering temperature of the substrate,effectively improve the high temperature strength.The effects of La_(2)O_(3)addition on the modification of cordierite—bonded silicon carbide porous ceramics were systematically researched.La_(2)O_(3)as a hexagonal close packed lanthanide rare earth elements can effectively inhibit the generation of cristobalite,promoting low temperature synthesis cordierite phase.When 0.6 wt%La_(2)O_(3)was added,a high three-point flexural strength of 62.26 MPa was achieved at an open porosity of 31.40%.However,too much La_(2)O_(3)addition produces a molten liquid will cause the value of the porosity and flexural strength of the ceramic material plunged.