The consolidation of ZrO2-SiC particle composites was studied. Thermodynamical considerations show that the stability region can be extended to higher processing temperatures by adjusting the sintering atmosphere. Densification behaviour, phase composition and microstructure development of such composites during sintering in different gas mixtures out of the Ar-CO-SiO system was studied. A process consisting of pressureless sintering in controlled atmospheres and subsequent containerless post-HIPing was developed which allows full density processing of these materials with up to 30 vol.% SiC particles without any additional sintering additives.