AlN-Y_2O_3液相烧结碳化硅陶瓷

采用无压烧结,以AlN与Y2O3的摩尔分数为60%∶40%作为烧结助剂进行碳化硅液相烧结,得到致密的烧结体。研究不同添加剂含量和不同保护气氛对烧结工艺的影响,并对烧结体的显微形貌和相进行分析。结果表明,高烧结助剂含量可在较低温度下实现致密化,但高温下液相挥发导致密度降低。与氩气作为保护气氛相比,氮气可抑制氮化铝的分解反应,有利于烧结。烧结体的晶粒均匀、细小,第二相均匀分布。烧结体的主相为6HSiC,并有氧氮化物的生成。

Liquid phase sintered silicon carbide with AlN-Y_2O_3

Silicon carbide was densified by liquid-phase sintering mechanism with AlN∶Y2O3 60%∶40% molar ratio as sintering additive via presureless sintering.The effectives of additive content and protect atmosphere was studied in detail.The phase properties and microstructure of sintered samples were investigated by SEM and XRD.The results show that sample with higher additve content can be densified at lower temperature,but at high temperature density decreases because of decomposition of liquid phase.Comparing with argon,nitrogen as protect atmosphere can inhibit decomposition of AlN,and is beneficial to sintering process.SEM analysis of sintered sample showes a fine grained microstructure with equiaxed grains.XRD analysis showes that the main phase of sintered sample is 6HSiC and complex phase of oxynitride can be found.