In-situ consolidation of nanocrystalline aluminium by ball milling

Abstract

Bulk nanocrystalline aluminium spheres were produced by in situ consolidation of commercially pure aluminium powder by ball milling at room temperature. The effect of four milling variables on the in situ consolidation process was studied changing only one parameter from the initial set of values (0.4% EBS, 160 rpm, 20 BPR, 20 h effective milling time). A maximum in the mode value of the spheres size distribution was observed for each variable (near to 0.4% EBS, 20 BPR, 190 rpm and 25 h of effective milling time), and other local maximum was also observed in some cases. Although the size distribution mode reaches the maximum value for the highest studied values of BPR (35) and effective time (100 h), the aluminium percentage adhered to balls and container during the milling is high and the process efficiency diminished sharply, which advises to not explore these regions.