Crystallite Size Refinement of ZrB2 by High-Energy Ball Milling
Abstract:The high-energy ball milling behavior of a commercially available ZrB2 powder was studied by X-ray diffractometry and transmission electron microscopy. It is shown that ball milling is very effective in obtaining nanocrystalline ZrB2 powder. Further, the crystallite size refinement occurs through repeated brittle fracture, with the final crystal size being limited by a combination of the fracture strength of particles and the compressive stress induced by collision of balls. With this mechanism, the crystallite size first decreases rapidly, then gradually, and finally approaches to an asymptotic limit as the ball-milling time increases. Additionally, the higher the ball-to-powder weight ratio, the faster the decrease in the crystallite size and the smaller the ultimate crystallite size.
Document Type: Research Article
Affiliations: 1: Departamento de Física Aplicada, Universidad de Extremadura, Badajoz 06071, Spain 2: Departamento de Ingeniería Mecánica, Energética y de los Materiales, Universidad de Extremadura, Badajoz 06071, Spain 3: Department of Materials Science and Engineering, University of Connecticut, Storrs, Connecticut 06269
Publication date: December 1, 2009