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Ultrafine Ti(C,N)-based cermet was sintered by SPS from 1050℃ to 1450℃ and its sintering properties,such as porosity,mechanical properties and phase transformation,were investigated by optical microscopy (OM),scanning electron microscopy (SEM),X-ray diffraction (XRD),and differential scanning calorimeter (DSC).It is found that the spark plasma sintering properties of Ti(C,N)-based cermet differ from those of conventional vacuum sintering.The liquid phase appearance is at least lower by 150℃ than that in vacuum sintering.The porosity decreases sharply below 1 200℃ and reaches minimum at 1 200℃,and afterwards it almost keeps invariable and no longer increases.SPS remarkably accelerates the phase transformation of Ti(C,N)-based cermet and it has a powerful ability to remove oxides in Ti(C,N)-based cermets.Above 1 350℃,denitrification occurred.Fresh graphite phase formed above 1 430℃.Both the porosity and graphite are responsible for the poor TRS.
Ultrafine Ti (C, N) -based cermet was sintered by SPS from 1050 ° C to 1450 ° C and its sintering properties, such as porosity, mechanical properties and phase transformation, were investigated by optical microscopy (OM), scanning electron microscopy (SEM) , X-ray diffraction (XRD), and differential scanning calorimeter (DSC). It is found that the spark plasma sintering properties of Ti (C, N) -based cermet differ from those of conventional vacuum sintering. Liquid phase appearance is at least lower by 150 ° C than that in vacuum sintering. The concentration decreases sharply below 1 200 ° C and reaches minimum at 1 200 ° C, and afterwards it almost keeps invariable and no longer increases .PS remarkably accelerates the phase transformation of Ti (C, N ) -based cermet and it has a powerful ability to remove oxides in Ti (C, N) -based cermets. Above 1 350 ° C, denitrification occurred. Fresh graphite phase formed above 1 430 ° C.Both the porosity and graphite are responsible for the poor TRS.