Effect of ball milling on the powder characteristics and welding mechanism of Mg2B2O5w/6061Al matrix composite

Abstract

Mg2B2O5w/6061Al matrix composites were fabricated through the powder metallurgy (PM) technique. The morphology of the particles, particle size and the effect of powder characteristics on densification behavior of the compacted samples were investigated. It was found that milling way, milling time, milling speed and whisker content all had different effects on powders characteristics and densification. During the low-energy milling process, the particles morphology changed from spherical to flattened shape and the reinforcement accelerated the process to some extent; during the high-energy milling process, the particles experienced the welding-fracturing process, the Al particles morphology changed from spherical to flattened shape and then back to more equiaxed morphology, the reinforcement whisker apparently accelerated the milling process. During the uniaxial cold pressing process, the particles after high-energy milling achieved better densification, the reverse for the low-energy milled powders because of whiskers clusters. A good linear correlation coefficient was obtained when the experiential data were fitted by the Panelli and Ambrosio Filho equation.