Abstract
Alumina was reduced using Nd:YAG laser ablation and generated aluminum was collected using cupper plate. The collected aluminum mass was estimated by volume of hydrogen gas evaporated in hydrochloric acid titration. Then, the energy conversion efficiency was calculated as the ratio of injected laser energy to that stocked in the collected aluminum. The efficiency was investigated as functions of the laser irradiation time, peak power and ambient pressure. For the irradiation time variation, the efficiency decreased after having taken a constant value for 500 sec. For the peak power variation, the efficiency became maximum as 25 % at 4.0 MW and decreased at 10 MW. For the pressure variation, the efficiency significantly decreased at 670 Pa though it was almost constant from the pressure of 1.3 Pa to 130 Pa.
