Refining of copper powder by a novel micro-abrasive milling method conducted in the air

Abstract

• Copper powder was refined by conventional milling and micro-abrasive milling. • Finer powder was prepared under the co-effect of micro-abrasives and oxygen. • The milled powder was converted into Cu 2+1 O with an average size of 375.4 nm. • The average size of the dispersed powder was reduced to 179.5 nm. • During the dispersion process, Cu 2+1 O was partly converted into CuO. The pure copper powder was milled by conventional high-energy ball milling (CM) and micro-abrasive milling (MAM) methods in the air or vacuum. The refining behavior of copper powder milled using these different methods has been studied, and the morphologies, microstructures, compositions, and properties of the milled powders have been thoroughly investigated. The results show that, as compared to CM, the MAMed copper powder had a better refinement behavior and contained a smaller number of agglomerates. After milling in the air for 30 h by MAM, whole copper powder was converted into Cu 2+1 O. In addition, under the synergistic effects of micro-abrasion and exposure to oxygen, the Cu 2+1 O powder was soft-agglomerated and had a specific surface area of 15.1031 m 2 /g and an average size of 375.4 nm. During the dispersion process, Cu 2+1 O was partly converted into CuO and the microstructural evolution characteristics were disclosed. The dispersed powder had an average particle size of 179.5 nm. The refining mechanism of the copper powder prepared by the micro-abrasive milling method was also discussed.