A novel method for the production of metal powders without conventional atomization process

Fabrication of Al alloy powders from recycling chips by mechanical milling is a novel processing technique. In this study, the mechanical milling was applied to the production of AA7075 powders from the recycling chips. The effect of milling time on the morphology, particle size and powder yield of the milled chips and fabricated powders was investigated. Fabricated powders were characterized by a scanning electron microscope (SEM), a Laser Particle Size Analyzer, X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). A chip milling model based on the morphology and size of milled powders were presented. It was found that after 10 h of milling, the average particle size of the AA7075 powders was reduced to 35 mu m. Results showed that 5 h of milling was the critical milling time in a change in the chip morphology (segmented shape) from powder morphology (irregular shape). The particle size of fabricated powders after 10 h of milling was about 286 times lower than that of initial chips. Crown Copyright (C) 2015 Published by Elsevier Ltd. All rights reserved.