高纯硅粉固相阶段氮化特征的研究

发布时间：2018-08-14 15:39

【摘要】：高纯硅粉氮化和普通硅粉氮化过程具有明显差别,在相同氮化时间,高纯硅粉氮化率明显低于普通硅粉;高纯硅粉氮化具有明显阶段性特征,可分为反应形核期、快速氮化期,速率减缓期和缓慢氮化期,而普通硅粉氮化的阶段性并不明显;高纯硅粉氮化前期产物以α-Si_3N_4相为主,在氮化后期,前期生成的氮化硅阻隔了氮气和硅粉直接接触,氮化明显变慢,产物主要为β-Si_3N_4,晶粒生长主要发生在基面上,而柱面生长缓慢,晶粒呈长径比较大的细长棒状。普通硅粉氮化时氮化硅晶粒生长不仅发生在基面,同时也发生在柱面上,前期生成的氮化硅并不能阻隔氮气和硅粉直接接触,其产物始终以α-Si_3N_4相为主,氮化硅颗粒的形状从短柱状至长柱状都有分布,柱面和基面同时生长是氮化较快的主要原因。
[Abstract]:The nitridation rate of high purity silicon powder is obviously lower than that of common silicon powder at the same nitriding time, and the nitridation of high purity silicon powder has obvious phase characteristics, which can be divided into reaction nucleation stage and rapid nitriding stage. The phase of nitridation of ordinary silicon powder was not obvious, and the product of nitridation of high purity silicon powder was 伪 -Si _ 3N _ 4 phase. In the later stage of nitridation, the silicon nitride produced in the early stage blocked the direct contact between nitrogen gas and silica fume. The nitridation became slower obviously, the main product was 尾 -Si _ 3N _ 4, the grain growth mainly occurred on the base plane, while the cylinder growth was slow, and the grain size was thin and long rod shape with large length and diameter. The grain growth of silicon nitride occurs not only on the base surface but also on the cylinder during nitridation of common silicon powder. The silicon nitride produced in the early stage can not block the direct contact between nitrogen gas and silicon powder, and the product is always 伪 -Si3N4 phase. The shape of silicon nitride particles is distributed from short column to long column. The main reason of rapid nitridation is the simultaneous growth of cylinder and base surface.
【作者单位】：沈阳工业大学材料科学与工程学院;
【基金】：国家自然科学基金(51472167)
【分类号】：TQ127.2

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