Processing and characterization of porous Ti2AlC with controlled porosity and pore size

In this work, we demonstrate a simple and inexpensive way to fabricate porous Ti2AlC, one of the best studied materials from the MAX phase family, with controlled porosity and pore size. This was achieved by using NaCl as the pore former, which was dissolved after cold pressing but before pressureless sintering at 1400 °C. Porous Ti2AlC with samples a volume fraction of porosity ranging from ∼10 to ∼71 vol.% and different pore size ranges, i.e. 42–83, 77–276 and 167–545 μm, were successfully fabricated. Fabricated samples were systematically characterized to determine their phase composition, morphology and porosity. Room temperature elastic moduli, compressive strength and thermal conductivity were determined as a function of porosity and/or pore size. For comparison, several samples pressureless-sintered without NaCl pore former, or fabricated by spark plasma sintering, were also characterized. The effects of porosity and/or pore size on the room temperature elastic moduli, compressive strength and thermal conductivity of porous Ti2AlC are reported and discussed in this work. It follows that porosity can be a useful microstructural parameter to tune mechanical and thermal properties of Ti2AlC.