粉煤灰空心微珠氮化反应合成O′-Sialon粉的研究

Synthesis of O'-Sialon Powders by Nitridation of Fuel Ash

以粉煤灰空心微珠、金属硅粉为原料,采用氮化反应工艺合成了O′-sialon粉体。研究了原料配比、氮化温度等对合成O′-sialon粉体的影响。结果表明,在1350～1500℃可以氮化反应合成O′-sialon,其最佳的合成温度为1450℃,合成产物中O′sialon的纯度较高;硅粉的用量对O′-sialon的合成影响不明显。O′-sialon粉体的显微结构观察结果表明:1350～1450℃氮化合成的O′-sialon粉体都已经失去了粉煤灰空心微珠的原始形貌,相互粘连在一起,反应产物中仅存在少量O′-sialon空心球,其粒径约为100μm。

O′-sialon hollow powders were synthesized by nitridation of fuel ash and Si. The effects of ratios of the reactants and the nitridation temperature on the formation of the O′-sialon hollow powders were studied. The nitridation reaction conducted between 1350-1500 ℃ yielded pure O′-sialon hollow powders, with the optimized temperature 1450 ℃. The amount of silicon had little effect on the formation of the powders. SEM results showed that most of the O′-sialon powders lost the hollow structures after nitridated at 1350-1450 ℃, and only small amount of O′-sialon hollow spheres smaller than 100 μm could be observed in the products.