Cu对铝热法制备的Fe3Al-10％Ni块体纳米晶材料组织和性能影响

摘要

通过铝热法制备了Cu含量为2％,4％,6％(质量分数,下同)的Fe3Al-10％ Ni块体纳米晶材料,用光学显微镜(OM),电子探针(EPMA),X-射线衍射仪(XRD)和透射电镜(TEM)表征了材料的微观结构,并测定了材料的维氏硬度和室温压缩性能.结果表明:Cu含量低(2％)时,合金保持无序bcc结构,晶粒尺寸显著下降；高Cu含量(4％和6％)使合金发生B2型有序化转变.添加Cu元素提高了材料的硬度,但不利于材料塑性的提高.添加2％和6％的Cu元素使材料的屈服强度明显增加,而添加4％的Cu元素使材料的强度明显下降.%Effects of Cu additions on microstructure and mechanical properties of Fe3Al-10% Ni bulk nanocrystalline prepared by alu-minothennic reaction were studied. The microstructure was studied by OM,EPMA,XRD and TEM, and the hardness and compressive strength were measured. The results reveal that the low Cu content (2% ) maintained the bcc crystal structure and resulted in a sharp decrease of the average grain size. However, high Cu contents (4% and 6% ) caused the structure ordering to B2. The hardness increased after adding Cu. A high Cu content was not benefit to the plasticity. The yield strength increased slightly at 2% and 6% Cu, but decreased a lot at 4% Cu.