In-situ compaction and sintering of Al2O3 - GNP nanoparticles using a high-frequency induction system

In-situ compaction and sintering of nanopowders are of great interest with respect to industrial production because they save time and energy. As a key study, Al2O3-1 wt.-% GNP composites were mixed in a V-type mixer for 2 hours at 35 cycle/min to obtain homogeneous mixtures. Mixed graphene nanoplatelets and alumina nanoparticles were compacted and sintered in-situ by applying uni-axial pressure in a graphite die, heated and generated by the ultra high-frequency induction system (UHFIHS). The graphite die was heated to 1500, 1550, 1600 and 1650 degrees C for 5, 10 and 20 minutes under a vacuum. The effect of sintering temperature and time on density, surface roughness, hardness and the microstructure of in-situ sintered nano graphene-alumina compacts were investigated.