用高岭土合成Sialon粉末的无压烧结

来源期刊：中国有色金属学报1999年第2期

论文作者：梁英 刘槟 黄和平 彭昶

文章页码：330 - 334

关键词：Sialon粉末 烧结助剂 Sialon陶瓷材料

Key words：sialon powder ; sintering additive ; sialon ceramic materials

摘    要：概述了Sialon陶瓷材料制备方面的研究。以高岭土为主要原料 ，采用碳热还原-氮化法合成的Sialon粉末为主要原料，分别添加Y₂O₃-Al₂O₃ 系与Al ₂O₃-MgO系两种烧结助剂后进行充分混合，混合物粉末在钢模中冷压成两种压坯试样a和b， 然后在N₂气氛中进行无压烧结。对烧成温度与烧结体体积密度的关系，烧结助剂的作用以及Sialon粉末无压烧结致密化过程进行了重点讨论。实验结果表明，分别添加10% Y₂O₃-5%Al₂O₃和10% Al₂O₃-5%MgO(均为质量分数，%)两种烧结助剂的试样a 和b分别在1620 ℃和1590 ℃烧成温度下，获得了致密的Sialo n陶瓷材料。并且建立了Sialon粉末无压烧结致密化模型，即lg(ΔV/V₀)∝lg t，其致密化过程分为颗粒重排与溶解-析出两个阶段，且扩散为全过程的控制性步骤。

Abstract: The development of technology on sialon ceramic materials was reviewed.The samples made from the mixtures of proper additives, such as Y₂ O₃-Al₂O₃ and Al₂O₃-MgO, and sialon powder prepared from Kaolin through the carbothermal reduct ion and nitridation process have been sintered under N₂ atmosphere.Relationship between volume density of samples and sintering temperature, effects of sintering additives and the densification procedure of pressless sintering of sialon powder were investigated. The results showed that the densified sialon ceramic materials could be obtained , when 10%Y₂O₃+5% Al₂O₃ and 10%Al₂O₃+5%MgO(all in mass fraction) were added in the mixtures respectively, under N₂ atmosphere, soaking4h at 1620℃ and 1590 ℃ respectively. Besides, the densification mode of pressless sintering of sialon powder was established that was lg(ΔV/V₀)∝lg t, of which densification procedure included grains reconstruction and dissolution-precipitation, and the diffusion is the crucial step during the whole densification procedure.