高能球磨中促进粉体细化的主要因素研究

Study on the Main Promotion Factors of Powder Refinement in High-energy Ball Milling

高能球磨技术作为一种制备包括纳米粉体在内的多种亚稳相材料的有效方法,已获得广泛应用。通常可以添加过程处理剂或在低温下球磨来抑制球磨过程中的冷焊,促使粉末细化。利用外加物理能场辅助高能球磨,使物理能与机械能协同作用到粉末,也是提高高能球磨效率的一种有效途径。根据不同条件下Fe粉的球磨细化结果,分析了高能球磨中过程处理剂、低温和外加能场辅助等主要促进粉体细化的因素及其作用。研究表明,采用等离子体辅助球磨仅仅10h,铁粉颗粒就被细化到了100nm。这种高的细化效率是因为等离子体辅助球磨中,等离子体对粉体产生的热爆效应和热应力的协同作用使粉体更易细化。

High-energy ball milling is an effective process to synthesize various materials with non-equilibrium microstructure including nano-powder and has been applied extensively. In order to limit cold welding and promote powder refining, process control agent or cryomilling is used. It is also an effective way to accelerate ball milling using external physics energy fields as assistant which can act on the powders cooperating with mechanical energy. Based on the results of Fe powder refining, the main promotion factors of powder refinement in high-energy ball milling are studied, such as process control agent, low temperature and external energy fields. Only 10h is required for Fe particles to reach lOOnm by plasma-assisted ball milling. The high efficiency of refinement is resulting from the hot explosion effect and thermal stress brought up by the plasma during assisted ball milling.