Densification Process of Spark Plasma Sintering for Silicon Carbide Ceramic

The silicon carbide ceramic with submicron silicon carbide powder as raw matevials and 10%Al2O3 and Y2O3 additions was fabricated by spark plasma sintering (SPS).The densification process was analyzed and effects of temperature,pressure and time on densification were investigated.The Microstructure and phase transformation were observed by XRD and SEM.The results show that sintering process could be separated into deflation swelling zone,gas overflow zone,sintering shrinkage zone and sintering accomplishing zone.The optimal relative density of 99.09% could be achieved at 1 600℃,50 MPa,for holding 5 min.