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在1200-1400°C下采用热压扩散的方法制备BN包覆Al2O3纤维增强NiAl基复合材料,利用扫描电子显微镜(SEM)和透射电子显微镜(TEM)研究其界面的显微结构和化学热稳定性。结果表明,在BN层与Ni25.8Al9.6Ta8.3的界面处发生了元素的扩散并伴随有复杂的化学反应发生。在NiAl和BN界面形成了连续的AlN层,Cr原子扩散到BN层中与B发生反应生成Cr5B3,还有小量的富Ta相在近NiAl侧界面处生成。
BN clad Al2O3 fiber reinforced NiAl matrix composites were prepared by hot-press diffusion at 1200-1400 ° C. The microstructure and chemical thermal stability of the interface were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) Sex. The results show that elemental diffusion takes place at the interface of BN layer and Ni25.8Al9.6Ta8.3 with complicated chemical reactions. A continuous AlN layer was formed on the interface of NiAl and BN. Cr atoms diffused into the BN layer to react with B to form Cr5B3. A small amount of Ta-rich phase was formed near the interface of NiAl.