Synthesis of Al2O3-Cu Nanocomposite by Dispersion and Reduction of Cu Oxide

Abstract

An investigation was made as to whether Al2O3/Cu nanocomposite powder can be optimally prepared by dispersion and reduction of Cu oxide, and suitably consolidated by employing pulse electric current sintering (PECS) process. a-Al2O3 and CuO powders were used as elemental powders. In order to obtain Al2O3 embedded by finely and homogeneously dispersed CuO particle, the elemental powders were high energy ball milled at the rotating speed of 900rpm, with the milling time varying up to 10h. The reduced powders were heat treated at 350oC in H2 atmosphere for 30min to reduce CuO into Cu. The reduced powders were subsequently sintered by employing PECS process. The composites sintered at 1250oC for 5min showed the relative density of above 98%. The fracture toughness of the Al2O3/Cu nanocomposite was as high as 4.9MPa.m1/2, being 1.3 times the value of pure Al2O3 sintered under same condition.