Microchanneled biomorphic AlN-coated Al2O3 by pressureless infiltration-nitridation

Microporous Al2O3/AlN composites with aligned channels were fabricated by pressureless infiltration nitridation of Al-Mg alloy into biomorphous Al2O3 preforms. The biomorphous Al2O3 was produced by Al-vapor infiltration in pyrolyzed rattan templates with subsequent oxidation. Infiltration nitridation was performed using an AlMg3 alloy infiltrated into the porous Al2O3 under flowing N-2. After infiltration-nitridation into the porous Al2O3 templates a composite consisting of AlN and Al2O3 as major phases was obtained. Nitidation of Al in these conditions led to hollow hexagonal AN crystals, which coated uniformly the Al2O3 channels surface. An increase of the BET specific surface area after infiltration nitridation of Al into the biomorphous Al2O3 was observed. Microchanneled Al2O3 coated with AN may be used as substrates in microelectronic applications that require high thermal conductivity and low dielectric constant. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.