约束电爆过程中石墨的纳米化机制

Nanocrystallization mechanism of graphite during constrained electric explosion

利用自行研制的约束电爆石墨制备低维纳米碳装置,通过改变初始充电电压与约束管管径进行系列性电爆实验,实验中对气溶胶形式的电爆产物进行原位取样,并进行显微分析.结合电爆产物显微分析结果和约束管中能量密度与电爆产物粒径间的关系,对电爆过程中石墨的纳米化机制进行研究.研究结果表明:电爆过程中约束管内产生的机械压缩波能够对石墨施加瞬间高压使石墨碎化,这一压缩波在传播过程中对已碎化的石墨进行反复冲击与剥离,从而导致石墨颗粒从约束管中喷射而出.在喷射过程中,石墨颗粒之间以及石墨颗粒与约束管壁之间不断发生碰撞,致使石墨颗粒进一步碎化,并形成低维纳米碳.

To prepare low-dimensional nano-carbon,a series of electric explosion tests were conducted with a self-developed constrained explosive graphite device by the changed initial charging voltages together with diameters of the constrained pipe.In the experiment,in-situ sampling and microscopic analysis were carried out successively for electro-explosion products in the form of aerosols.On this basis,nano-crystallization mechanism of graphite in the process of electric explosion was studied by combining the results of the microscopic analysis of the products and the relationship between the energy density and the particle size of the products.The results show that the mechanical compression are generated in the constraint tube can exert instantaneous high pressure on the graphite and make the graphite broken.The compression wave repeatedly impacts and peels the broken graphite off in its propagation process,which results in the graphite particles ejecting from the tube.During particle injection,the collision between the graphite particles as well as between the graphite particles and constraint tube wall occurs constantly,resulting in further fragmentation of the graphite particles and formation of low dimensional nano-carbon.