Abstract
The synthesis of Al2O3-Ni3Al cermets with interpenetrating networks have been made by the pressureless reaction sintering process. The synthesis is performed by solid-state reaction of intensively ball milled Al + Ni + Al2O3 powders. The mixtures are heat treated in an inert atmosphere (N2) such that the exothermic reaction between Ni and Al takes place in a controlled manner essentially at temperatures below the melting point of Al. Dense and homogeneous microstructures were obtained with an Al2O3 matrix and a Ni3Al intermetallics reinforcement. Thermodynamic calculations indicate that the cermet can be fabricated for in situ reaction synthesis, wich suggest that pressureless reaction sintering process may be a general route to cermet synthesis with the prospect for the production of cermets with interpenetrating networks. The present paper discusses processing details for the obtention of the mentioned cermet.
