Microstructure and mechanical properties of gel casted Ti3AlC2

Abstract

Dense Ti3AlC2 components with a complex shape were fabricated using gel casting followed by pressure-less sintering. Low viscosity slurry was prepared using an aqueous based acrylamide (AM) monomer with a 50% solid loading. Homogeneous and crack free Ti3AlC2 green bodies were obtained. The sintering temperatures were set at 1500, 1550 and 1600 °C, highest relative density of 93% was achieved at 1550 °C. Surprisingly, samples sintered at 1600 °C resulted in a drop of relative density because of the abnormal grain growth and entrapped porosity. The pressure-less sintered samples had mechanical properties comparable to hot pressed counterparts with Vickers hardness of 3.1 ± 0.2 GPa, fracture toughness of 4.2 ± 0.2 MPa m1/2 and flexural strength of 302.3 ± 25.0 MPa. Final machining was still required to obtain a net shape components free from surface defects.