反应烧结制备多孔β-sialon/Si3N4陶瓷

POROUS β-SIALON/Si_3N_4 CERAMICS PREPARED BY REACTIVE SINTERING

以Si粉和Al2O3空心球为原料,采用反应烧结后高温烧结法制备了多孔β-sialon/Si3N4陶瓷。X射线衍射结果表明:在0.25MPa的氮气压力下于1300℃反应烧结2h后在0.25MPa的氮气压力下1700℃及1750℃高温烧结2h,制备的样品的组成为β-sialon(Si6-zAlzOzN8-z,z=3)及β-Si3N4,随着烧结温度由1700℃升高至1750℃,β-sialon的相对质量分数由29.9%增加至56.8%。场发射扫描电镜观察结果表明:1750℃高温烧结样品的显微结构由大孔β-sialon及疏松的β-Si3N4基体组成。1750℃高温烧结后,样品的气孔率为28%,抗弯强度为92.5MPa。

Porous β-sialon/ Si3N4 ceramics were fabricated by resintering after reactive sintering at 1 300 ℃ for 2 h with a pressure of 0.25 MPa using Si powder and Al2O3 hollow sphere as raw materials. X-ray diffraction analysis proves that the phase compositions of the samples resintered at 1 300 ℃ for 2 h in nitrogen gas are β-sialon （Si6-zAlzOzN8-z,z = 3） and β-Si3N4 after soaking the sample at 1 700 and 1 750 ℃ for 2 h. The mass fraction of β-sialon in the sintered body increases from 29.9% to 56.8% with increasing sintering temperature form 1 700 to 1 750 ℃. The field emission scanning electron microscope observation results indicate that the microstructure of the sample consists of β-sialon with large pore and porous β-Si3N4 matrix. The sample sintered at 1 750 ℃ for 2 h has a porosity of about 28% and a bending strength of 92.5 MPa.