α-SiAlON陶瓷近烧结温区显微组织演变分析

Microstructure Evolution of α-SiAlON Ceramic in Near Sintering Temperature Range

为了研究α-SiAlON陶瓷近烧结温度范围内显微组织变化并分析其断裂形貌,以α-Si3N4、Al2O3及AlN作为形成α-SiAlON相的主要原料,以Y2O3作为烧结助剂,采用冷等静压成型及无压烧结工艺制备了α-SiAlON陶瓷。利用XRD分析试样相组成,用SEM观察试样显微组织形貌,用EDS分析试样的元素组成。结果表明:利用国产Si3N4粉体在1800℃烧结能够形成α-SiAlON相、短柱状颗粒形成阶段是粉末转化为柱状晶的过渡阶段、SiAlON相柱状晶的三维乱序堆叠可以有效提高陶瓷基体的抗裂纹扩展能力,进而提升陶瓷的强度和韧性。

In order to study its microstructure change and fracture morphologies in near sintering range, α-SiAlON ceramic was fabricated by cold isostatic pressing and pressureless sintering, using α-Si3N4, Al2O3 and AlN as matrix powders, and Y2O3 as a sintering aid. Its samples were characterized by XRD, SEM and EDS. The results show that： α-SiAlON phase can be formed by sintering domestic α-Si3N4 particles at 1800℃; short columnar grains are formed during the transition from powders to columnar crystals; the disorderly three-dimensional stacking of α-SiAlON columnar grains can improve the crack resistance of the matrix, thus enhancing the strength and toughness of α-SiAlON ceramic.