Fe/Al_2O_3复合材料的制备和性能

Fabrication and Properties of Fe/Al_2O_3 Composites

用石墨埋烧方法制备Fe/Al_2O_3复合材料,对其力学性能和微观结构进行了分析。结果表明:Fe/Al_2O_3复合材料的弯曲强度与断裂韧性均随Al_2O_3含量的升高先升高后降低,当Al_2O_3含量(质量分数)为70%时,其弯曲强度与断裂韧性分别达到602.49 MPa和9.33 MPa·m^1/2,其硬度随Al_2O_3含量先降低后升高。在烧结过程中在Fe颗粒周围形成一种成分为FeO与FeAl_2O_4的壳体,在壳体与Fe颗粒之间存在微裂纹缺陷。壳体的形成和壳体与金属颗粒间的微裂纹钝化了外部应力,从而提高了复合材料的韧性。

The Fe/AI203 composites with different proportions were prepared by sintering buried in the graphite, the microstructure and properties of Fe/Al2O3 composites were analyzed. The results show that the bending strength and fracture toughness of Fe/Al2O3 composites increase with Al2O3 percent, and then decrease. The bending strength and fracture toughness of Fe/Al2O3 composites reach respectively 602.49 MPa and 9.33 MPa.m^1/2, when Al2O3 percent（mass fraction） is 70% The hardness of Fe/Al2O3 composites decrease with Al2O3 percent, and then increase. The shell composed of FeO and FeAl2O4 formed around Fe particles in the sintering process. Micro cracks exist between the shell and Fe particles. The external stress was cut by the shell and the micro cracks between the shell and Fe particles, then the fracture toughness of Fe/Al2O3 composites enhance greatly.