Al_2O_3粉末对MA-SPS制备Fe_3Al材料显微组织的影响

Effect of Al_2O_3 addition on microstructure of Fe_3Al compounds fabricated by MA-SPS method

采用机械活化-放电等离子烧结(MA-SPS)方法制备了Fe3Al材料,使用X射线衍射仪和电子显微镜对球磨粉体和烧结块体进行了研究。球磨之前加入纳米Al2O3粉末可以有效地细化烧结材料的显微组织,提高其力学性能。加入2%～5%(质量分数,以下同)Al2O3时,对显微组织的细化作用明显,材料的显微硬度提高,超过5%时,孔隙度上升,显微硬度下降。

Fe3Al compounds were fabricated by MA-SPS method. The phase identification was done by X-ray diffraction. The microstructures of the sintered samples were investigated by EPMA and SEM. The nano powders of Al2O3 introduced at the mechanical milling stage can effectively refine the microstructure of sintered sample, and improve mechanical properties, because the Al2O3 powders can refine the powders in the milling stage, and inhibit the grain growth in the sintering stage. With the addition of 2 %-5 % Al2O3, the microstructure is significantly refined, the microhardness continuously increased with the amount of addition. With the amount of addition more than 5 %, the porosity of the sample increases, and the microhardness decreases.