Electroconsolidation offers fast, low-cost densification

Injection Molding and Near-Complete Densification of Monolithic and Al2O3 Fiber-Reinforced Ti2AlC MAX Phase Composites

“…An additional densification step after the first PS step was also carried out by employing the approach of electroconsolidation of complex shapes [29][30][31][32][33], by using a graphite powder bed and field-assisted sintering technology/spark-plasma sintering (FAST/SPS). The parts pre-densified by PS at 1250 • C were placed in a graphite die and immersed in coarse graphite powder (−20 + 80 mesh, 99.9%, Alfa Aesar, Tewksbury, MA, USA).…”

“…Conventionally, hot isostatic pressing [28] is employed for metals and ceramics, but this is costly and often requires an encapsulation to avoid fluid penetration within the pores. Therefore, powder-bed sintering in graphite powder, using a FAST/SPS furnace [29][30][31][32][33], was found to be an alternative to achieving the near-full densification of complex shapes, as it granted the required driving force at a reduced sintering temperature (1200 • C) and dwell time (10-15 min). To the authors' knowledge, this procedure, when applied to MAX phases, is found nowhere in the literature so far.…”

“…Methods to densify complex shapes of non-sinterable materials are not plentiful and conventional hot isostatic pressing [28] can be costly and difficult to introduce for highly porous microstructures. A concept about the low-cost densification of complex assemblies in a particulate bed of refractory materials has emerged and seems promising [29][30][31][32][33], though it is, so far, totally uncharted for MAX phases.…”