Fabrication of Al2O3-Cu Nanocomposites Using Rotary Chemical Vapor Deposition and Spark Plasma Sintering

A two-step rotary chemical vapor deposition technique was developed to uniformly mix Cu nanoparticles with the gamma Al2O3 powders, and then the as-obtained powders were consolidated to Al2O3-Cu nanocomposites by spark plasma sintering. In the RCVD process, the metal-organic precursor of copper dipivaloylmethanate (Cu(DPM)(2)) reacted with O-2 and then was reduced by H-2 in order to erase the contamination of carbon. At 1473 K, the relative density of Al2O3-Cu increased with increasing C-Cu and the maximum value was 97.7% at C-Cu = 5.2 mass%. The maximum fracture toughness of Al2O3-Cu was 4.1 MPa m(1/2) at C-Cu = 3.8 mass%, and 1 MPa m(1/2) higher than that of monolithic Al2O3, validating the beneficial effects of Cu nanoparticles.