金属/聚合物转化陶瓷复合材料的原位反应合成和磁学性能研究

Study on magnetic properties of metal/polymer derived ceramic composites prepared by in-situ reaction

在高温转变陶瓷工艺过程中,通过不同金属元素(Ni、Mn、Co和Fe)的添加,原位反应合成出Si-C- N陶瓷基体的复合材料。由于金属元素的存在,使得所合成的复合材料的质量损失减小,密度增加。富金属相能均匀分布在基体材料中,复合材料无明显缺陷。XRD分析结果表明,Ni、Mn和Fe在高温分解过程中与基体都发生反应,分别生成了Ni_(31)Si_(12)、Mn_5Si_3和Mn_2N_(0．86)、Fe_3Si,而Co没有。由于这些不同富金属相的存在,使得复合材料的磁学性能在低温(77K)和室温(300K)有所不同。

Different metal elements Ni, Mn, Co and Fe were added into polymer-derived silicon carbonitride. The composites were prepared with in-situ reaction process. The weight loss of composites before and after pyrolysis is less than that of matrix and the density of composites is larger. The metal-rich phase can uniformly distribute in matrix and no flaw can be observed under SEM. XRD results show that Ni, Mn and Fe reacts with matrix except Co. The resultants between Ni, Co, Fe and matrix are Ni31Si12, Mn5Si3 and Mn2N0.86, Fe3Si, respectively. The magnetic properties of composites are different at 77K and 300K because of the different metal-rich phases in composites.