激光辐照石墨-镍悬浮液制备碳包覆颗粒的研究

Research on the synthesis of carbon coated particles by laser ablation in the graphite-nickel suspension

用球磨机湿法球磨微米级镍粉和石墨制备石墨与镍的悬浮液,然后用脉冲激光辐照。用扫描电镜、X射线衍射和透射电镜等对球磨和激光辐照后的产物进行表征。结果表明:球磨细化了镍粉,并使镍粉和石墨混合均匀,使其可悬浮于水介质中;然后激光辐照悬浮液得到了细小的碳包覆镍纳米颗粒。通过对碳包覆颗粒形成机制的初步探索,认为激光作用会使镍和碳气化并形成镍碳混合蒸气,在脉冲过后的冷却过程中碳和镍碰撞溶解,而温度的不断降低会促使过饱和的碳从镍中析出,从而形成包覆,获得了细小的碳包覆颗粒。

The graphite and nickel suspension were prepared by ball-milling the mieropartieles of graphite and nickel in liquid media. And carbon-coated nickel particle （CENP） were synthesized by millisecond-pulse laser irradiating in the suspension, the formation mechanism was also discussed and investigated. SEM, XRD, TEM were used to characterize the ball-milled and laser-ablated products. The results show that, through ball-milling suspension is obtained, when irradiating the suspension by laser, nickel and graphite will be evaporated synchronously, during cooling, carbon is precipitated from the solidified particle and forms a shell.