石墨烯含量对等离子烧结铝导体力学及导电性的影响

Effects of Graphene Content on the Mechanics and Conductivity of Plasma-Sintered Aluminum Conductors

综合运用超声分散与机械搅拌使石墨烯在铝粉中均匀混合,通过放电等离子烧结(SPS)方法制备石墨烯铝导体,并对其组织,力学及导电性展开实验测试。研究结果表明:铝基体内存在许多形态均匀的石墨烯片,并未出现团聚。改性后石墨烯大部分都分布于界面处,能够显著抑制铝导体的变形。添加石墨烯后等离子烧结制得的铝导体获得了更高的相对密度和硬度。将石墨烯添加到铝基体中后,力学强度获得了明显提高。铝基体组织中存在大量的片状石墨烯,当试样发生断裂后也继续保持原有片状形态。添加较低石墨烯试样电导率发生明显提升,在加入1%时达到了最高电导率。当加入0.5%石墨烯时,材料的导热性发生了大幅提升,随着石墨烯的含量超过1%石墨烯铝导体热导率变小现象。

Magnetic fluid can be used to seal other liquids but suffers from a limited lifetime due to the direct contact with sealed liquids,which can cause liquid-liquid interfacial instability.To improve the performance,a magnetic fluid seal equipped with a gas isolation device is designed,which can avoid direct interfacial contact.Theoretically,the sealing mechanism of the device is investigated;experimentally,a test rig of a magnetic fluid seal with gas isolation is built,and critical pressure and seal life for sealing water are carried out on the platform.Both theoretical and experimental results show that the lifetime is significantly enhanced,and it operates stably without leaking for no less than 120 hours at various shaft speeds.The sealing performance is considerably better than that of the original magnetic fluid seal.