2006 Volume 47 Issue 9 Pages 2172-2177
Intermetallic (Al-Ni) foams were fabricated by a combustion reaction of the blended powder compacts consisting of nickel and aluminum. The foaming agents (titanium and B4C powders) were added to the nickel and aluminum blended powder to produce foams with high porosity by increasing the combustion temperature. The effects of the size of elemental powders (aluminum and nickel), the powder blending ratio, the amount of foaming agent and compacting conditions on the porosity and pore morphology of the foams were investigated. The size of nickel powder was an important factor to produce foams by the combustion synthesis and it should be small enough to achieve high porosity. The size of the aluminum powder was not such an important factor. The uniform pore morphology in the foam was obtained only when the powder blending ratio was adequate. The proper addition of the foaming agent increased the porosity and the size of pores, and also stabilized the uniformity of the pore morphology. There was a threshold density of the precursor to achieve sufficient foaming. The pore diameter of a synthesized foam is increased with increasing precursor compacting temperature and pressure. An attempt was made to disperse fine ceramic particles in the foam materials. It was revealed that the addition of ceramic particles did not affect the porous structure.
