Rapid Preparation of Porous Ni–Al Intermetallics by Thermal Explosion

Porous Ni3Al, NiAl, and NiAl3 intermetallics have been synthesized through simple and rapid process of thermal explosion (TE) from 75 at.% Ni/25 at.% Al, 50 at.% Ni/50 at.% Al and 25 at.% Ni/75 at.% Al elemental powders. The effect of the three components on temperature profile, phase composition, pore structure, and oxidation resistance were investigated. The results showed that the temperature of the specimens increased rapidly from 638°C to 1381°C, 620°C to 1613°C and 642°C to 1172°C in a few seconds. X-ray diffraction patterns indicated that Ni3Al, NiAl, and NiAl3 were the main phase or single-phase compounds in the TE products. Porous Ni3Al, NiAl, and NiAl3 intermetallics showed variable pore structures. Moreover, all the products of three components exhibited good oxidation resistance, particularly the porous NiAl and NiAl3 intermetallics.