【作者】 黄少波；

【导师】 蒋明学；

【作者基本信息】 西安建筑科技大学 ， 材料学， 2011， 硕士

【摘要】 本文主要研究了纳米Al₂O₃和纳米Cr₂O₃对镁铬质耐火材料性能和结构的影响。在镁铬质耐火材料中分别加入不同量的纳米Al₂O₃和纳米Cr₂O₃粉体,研究了两种纳米粉对不同温度烧成的镁铬质耐火材料的烧结与力学性能的影响,同时借助扫描电镜和能量色散谱仪等手段对材料显微结构进行分析。结果表明:（1）加入纳米粉可有效改善镁铬质耐火材料的烧结性能、力学性能和抗热震性能,并且提高材料高温相的直接结合程度。烧成温度越低,纳米粉的加入对其性能影响就越显著。（2）加入适量纳米粉可以有效填充坯体颗粒中的纳米级空隙,提高坯体的密度,使得坯体更加致密。当纳米粉恰好能完全填充于坯体的纳米级孔隙中,对坯体性能提升最高,如加入过量,反而会降低其性能。本文中,4%的Al₂O₃和Cr₂O₃纳米粉均是最佳加入量。（3）纳米粉的加入能降低镁铬质耐火材料的烧成温度,4%纳米粉大约可降低100℃。（4）加入适量的纳米Al₂O₃和Cr₂O₃到镁铬质耐火材料中,对制品烧结性能和力学性能的影响不一样,加纳米Al₂O₃在1550℃其助烧结效果就已显露,但加纳米Cr₂O₃要到1650℃才显示出对烧结和力学性能的促进作用。更多还原

【Abstract】 The influences of nano-Al₂O₃ and nano-Cr₂O₃ on the properties and structure of magnesia-chrome refractory has been studied. Different amounts of nano-Al₂O₃ powders and nano-Cr₂O₃ powders were added to the magnesia-chrome refractory, the influences of this two different nano-powders on the sintering property and mechanical property by different temperature sintered has been studied, meanwhile, the microstructure of the material has been analysised by means of scanning electron microscopy and energy dispersive spectroscopy.The following conclusions have been reached:（1） The sintering property, mechanical property and thermal shock resistance of magnesia-chrome refractory have been improved by adding nano-powder, and direct binding of high temperature phase has been enhanced, the performance affected by the addition of nano-particles is more remarkable of lower sintering temperature.（2） The nano-gap in the reen body particles can be filled effectively by adding appropriate amount of nanoparticles, making the green body more compact and improving the density of green body. The green body has the highest performance when the nano-gap is filled completely if the number of nanoparticles are just appropriate, and the performance will be reduced if the nanoparticles are added excessively. Both the optimum dosage of Al₂O₃ and Cr₂O₃ nanoparticles are 4% in this paper.（3） The firing temperature of magnesia-chrome refractory can be reduced by adding nanoparticles, and it can be reduced about 100℃with 4% nano-powder.（4） The influences of adding nano-Al₂O₃ and nano-Cr₂O₃ to magnesia-chrome refractory on the sintering property and mechanical property of the products are different, the effects of sintering aid has been shown at 1550℃with adding nano-Al₂O₃ ,but at 1650℃with adding nano-Cr₂O₃ .更多还原