膨胀石墨对镁碳耐火材料显微结构和性能的影响  

Effect of Expanded Graphite on Microstructure and Properties of Mg O-C Refractories

作　　者：朱天彬[1] 李亚伟[1] 桑绍柏[1] 

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,武汉430081

出　　处：《硅酸盐通报》2015年第9期2436-2441,共6页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(51372176);国家"973"计划前期研究专项(2014CB660802);湖北省自然科学基金重点基金(ZRZ0348)

摘　　要：以膨胀石墨为碳源,部分取代镁碳耐火材料(含5wt%的鳞片石墨)中的鳞片石墨,借助X射线衍射仪、场发射扫描电镜、能谱仪以及三点弯曲测试仪等研究了膨胀石墨的添加对热处理后镁碳材料的显微结构、力学性能、抗热震性和抗氧化性的影响。结果表明:镁碳材料中引入0.2wt%的膨胀石墨在高温下可促进材料基体内片状Al N相形成,进而使试样的抗折强度和弯曲模量达到最大,分别为12.35 MPa和2.82 GPa;但是过量的添加将对材料的致密度产生负面影响,从而降低了材料的抗折强度和弯曲模量;膨胀石墨的添加显著提高了镁碳材料的抗热震性但对材料的抗氧化性不利;当膨胀石墨的加入量为0.5wt%时,镁碳材料的综合性能最好,若想加大膨胀石墨的添加量,需对其抗氧化性进行改善。Microstructure, mechanical properties, thermal shock resistance and oxidation resistance of MgO-C refractories （5wt% flaky graphite ） treated at different temperatures were investigated when expanded graphite （EG） was used as the carbon source to partially replace flaky graphite in the materials. The results showed that the addition of 0.2wt% EG promoted the formation of flake-like AIN in the matrix of MgO-C refractories and thus made them possess the highest cold modulus of rupture and flexural modulus （12.35 MPa and 2.82 GPa, respectively） , but excessive addition of EG had a negative influence on the density of such refractories and consequently decreased their cold modulus of rupture and flexural modulus. Also, the improved thermal shock resistance and decreased oxidation resistance were achieved due to the addition of EG. MgO-C refractories exhibited the best comprehensive performance when the amount of EG was 0.5wt%. Furthermore, the oxidation resistance of EG will need to be improved if the amount of EG used is increased in MgO-C refractories.

关 键 词：力学性能 抗热震性 抗氧化性 膨胀石墨 镁碳耐火材料 

分 类 号：TU54[建筑科学—建筑技术科学]