不同添加剂对石墨材料高温粘结性能的影响

Influences of Additives on the Adhesion of Graphite at High Temperatures

在以酚醛树脂(ＰＦ)和碳化硼(Ｂ４Ｃ)为原料的高温粘结剂基础上,Ａｌ２Ｏ３,Ｓｉ和白炭黑(超细ＳｉＯ２)作为第二种添加剂分别加入到粘结剂中以制备新型高温粘结剂,并对石墨材料进行粘结．用新型高温粘结剂粘结的石墨部件分别在２００、８００、１５００℃下热处理,并在室温条件下测试其剪切强度．结果表明,复合添加剂对石墨粘结部件的粘结性能有明显的影响．其中,酚醛树脂＋Ｂ４Ｃ＋白炭黑粘结剂具有较为理想的粘结性能,白炭黑的添加对提高石墨材料的高温粘结性能具有明显的作用．

Based on the high temperature adhesive (HTA) composed of phenol-formaldehyde resin(PF) and boron carbide (B4C) ceramic powders, new high temperature adhesives (HTAs) were prepared by using secondary additives, aluminium oxide (Al2O3) or silicon (Si) or fumed silica (SiO2) as additives to modify the properties of the adhesives. Graphite components bonded by the above adhesives were heat-treated at different temperatures ranged from 200 degreesC to 1500degreesC. Subsequently their adhesive shear strengths were tested at room temperature. Results show that the additives have an obvious influence on the adhesion properties of bonded graphite components. In additional, fumed silica has a great effect on improving the adhesion property of HTA, and the adhesive consisting of phenol-formaldehyde resin, boron carbide and fumed silica has satisfied adhesive strength.