摘要
为实现石墨材料的高温连接,以酚醛树脂(PF)为胶黏剂主体,B4C、石墨作复合改性填料,配制得到超高温胶黏剂。分别将PF和超高温胶黏剂热模压成型,测试了200-1 200℃间不同温度高温热处理后热压样的电导率及抗压强度。发现PF及高温胶本体的电导率随温度升高而提高,在600-800℃间高温胶的电导率发生突变而迅速提升,1 000℃以后电导率仍小幅提高并趋于稳定。树脂基体的高温裂解是超高温胶电导率随温度上升的关键原因,石墨粉的加入能显著提高超高温胶的导电性,B4C的过量加入则对超高温胶的高温导电性有不利影响。为进一步验证高温胶的导电性能,以超高温胶黏剂粘接石墨样品,在相同条件下进行高温热处理并测试了胶层的电导率,发现了同样的规律。综合考虑力学性能和导电性能,将较为理想的胶黏剂配比(质量比)优化确定为mPF:mB4C:m石墨=100:75:25。
In order to realize joining of carbon/graphite materials which usually happens at high temperatures, we prepared ultra-temperature adhesives （UTAs） using phenol formaldehyde （PF） as matrix with boron carbide （B4C） and graphite powders as additives. The pure PF and UTAs were cured by the hot-pressing method. After heated at 200-1 200 ℃, the room-temperature electrical conductivities of these hot-pressed samples were tested. It was found that the electrical conductivities of these hot-pressed samples increased with elevated temperatures. The electrical conductivity increased rapidly in the range of 600-800 ℃ and then tended to be stable at above 1000 ℃. The electrical conductivities of graphite specimens bonded by UTAs were further investigated after the heating trealment under the same condition. The evolution regularity of electrical conductivity for the bonded specimens is similar to that of hot-pressed samples. It also indicates that the UTAs prepared with a composition of m（PF）： m（B4C）： m（graphite powders）=100： 75：25 had preferable mechanical and electrical properties. conductivity
出处
《中国科技论文》
CAS
北大核心
2012年第3期175-180,共6页
China Sciencepaper
基金
国家自然科学基金资助项目(20874011)
教育部留学回国人员科研启动基金(教外司留[2009]1001号)
高等学校博士学科点专项科研基金资助项目(20100092110030)
关键词
酚醛树脂
碳化硼
石墨
超高温胶黏剂
导电
phenol formaldehyde
boron carbide
graphite
ultra-temperature adhesive
electrical
