MAX phase foams produced via powder metallurgy process using water soluble space holder

Abstract

There have been few systematic studies of the fabrication and properties of porous MAX phase microstructures despite the potential applications of these materials. A simple, low cost, eco-friendly PM method has been developed to prepare MAX phase foams from commercial Ti₂AlC powder, using crystalline carbohydrate as space holder. This method involves: mixing Ti₂AlC powder with crystalline carbohydrate, pressing to form a green body, removal of the space holder and sintering. Compaction was achieved by uniaxial pressing (UP) and cold isostatic pressing (CIP). Control of porosity was achieved by varying the particle size (three ranges between 250 and 1000 μm), and volume fractions (20, 40 and 60%) of space holder. The foams were characterised and the porosity compared with the expected values. Optimal conditions for this novel processing technique were established with the aim of controlling the final microstructures and properties of the Ti₂AlC foams.