Microstructure And Properties Of Co-Al Porous Intermetallics Fabricated By Thermal Explosion Reaction

Co-Al porous intermetallics were fabricated by an efficient and energy-saving method of thermal explosion (TE) reactions. The effects of Co/Al molar ratios on the temperature profiles, phase compositions, expansion behaviors, density, pore characteristics, and oxidation resistance were investigated. When the target furnace temperature was set at 700 degrees C, there was an obvious exothermic peak in the temperature profiles. The ignition temperatures were in the range of 600-645 degrees C, and the combustion temperatures were in the range of 984-1,421 degrees C. Co-Al porous intermetallics had the open porosity of 27-43%, and the pores were from nonfully dense green compacts and explosion behaviors of TE. The specimen with Co:Al = 2:9 possessed a higher open porosity of 42.8%, the lowest density of 1.86 g cm(-3), and the largest volume expansion of 76.7%. The porous specimens with Co:Al = 1:1 possessed the highest open porosity of 43.2%, the lowest volume expansion of 12.3%, and the highest density of 3.42 g cm(-3). All Co-Al porous intermetallics showed excellent oxidation resistance at 650 degrees C in air, especially the specimen with Co:Al = 1:1 had the highest oxidation resistance.