The preparation and structural characterization of Al2O3/Ni-P composites with an interpenetrating network

This paper reports on the possibility of obtaining 3D interpenetrating ceramic-metal composites by using an electroless chemical plating method. Alumina powder was coated with a homogenous Ni-P alloy layer to obtain Al2O3/Ni-P composites. The coated powders were consolidated via hot pressing (HP) under high pressure at different temperatures below the melting point of the metal phase. High-resolution scanning electron microscope (HRSEM) and X-ray diffractometry (XRD) techniques were used to study the influence of the consolidation conditions (temperature and pressure) on the microstructure of the composites. The percolation of the interpenetrating phases was evaluated by computer-aided image analysis and electrical conductivity measurements. The results indicate that the use of electroless nickel plating allows for the fabrication of uniform 3D interpenetrating, continuous metal-ceramic composites. The metal phase fills the open pores and also interpenetrates the spaces between the ceramic grains. Depending on the consolidation conditions it is possible to obtain dense or porous materials with a promising metal phase nanostructure. (c) 2006 Elsevier Ltd. All rights reserved.