Abstract
Tumbler-ball milling of Al powder was carried out to investigate the effect of milling conditions on the characteristics of Al flake powder particles for fingerprint detection. Initial powder of under 25μm was more easily developed to flake particles have high specific surface area than under 19μm one. With an increase in the ball size from 4.8 to 16mm, the specific surface area of the milled powder particles increases and then decreases at 16mm. The specific surface area of the milled powder particles increased with increasing mill container rotation speed. The excellent fingerprint detection qualities were obtained in milling condition of under 25μm initial powder, 9.5mm ball size, 80rpm mill container rotation speed and 40 hours milling time. The diameter of the flake particles estimated from the impact velocity of the balls based on the milling ball dynamics and the Hertz contact theory was compared with the measured one.
