放电等离子烧结工艺制备致密碳化硅陶瓷
Densification Process of Spark Plasma Sintering for Silicon Carbide Ceramic
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摘要: 以SiC微粉为原料,并添加质量分数为10%的Al2O3和Y2O3为烧结助剂,采用放电等离子烧结(SPS)技术快速制备了SiC陶瓷,对烧结致密化过程、SPS烧结温度、烧结压力及烧结时间对致密化的影响进行了研究,并通过XRD和SEM等检测手段对SPS烧结得到烧结体的显微组织和物相组成进行了分析.结果表明:SiC的SPS烧结过程可分为放气膨胀区、气体溢出收缩区、烧结收缩区、烧结完成区四阶段,最佳的烧结参数为1 600℃,50 MPa,5 min,所得的烧结体致密度达99.09%.Abstract: 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.