热压加工对含铬、镍块体纳米晶Fe_3Al组织和性能的影响研究

Effect of Hot Pressing on Microstructure and Mechanical Properties of Bulk Nanocrystalline Fe_3Al With Cr and Ni Element

对通过铝热反应熔化制备的含10%(质量分数,下同)的铬和10%镍的块体纳米晶Fe3Al材料在不同温度、不同次数下进行了热压加工。利用XRD研究了热压加工前后纳米晶粒尺寸的变化,并测试了硬度变化和压缩率。结果显示:含10%铬的纳米晶Fe3Al在600℃表现出较好的塑性变形能力,材料在热压加工前后都是由无序bcc结构的Fe3Al相组成;含10%镍的纳米晶Fe3Al在800和1 000℃表现出较好的塑性变形能力,材料在热压加工前为无序bcc结构的Fe3Al相,在1 000℃热加工后,已转变为DO3有序结构;两种材料的压缩率都随着热压加工次数的增加逐渐增大。含10%铬的纳米晶Fe3Al在600℃和含10%镍的纳米晶Fe3Al在1 000℃随着热压加工次数的增加,晶粒尺寸都发生了增大,但材料硬度变化不大。

Bulk nanocrystalline Fe3 Al materials with 10%Cr element and 10% Ni element made by aluminothermic reaction were hot pressed at different temperatures and times. Grain sizes of the materials were investigated by XRD. Hardness and compressibility were also tested. Results show that the nanocrystalline Fe3 Al materials with 10%Cr element exhibit good plasticity at 600℃ and the materials mainly consist of Fe3 Al phases with disorder bcc crystal structure before and after hot pressing. The nanocrystalline Fe3 Almaterials with 10%Ni element exhibit good plasticity at 800 and 1000℃. The materials mainly consist of Fe3 Al phases with disorder bcc crystal structure before hot pressing and turn into Fe3 Al phases with DO3 crystal structure after hot pressing at 1 000℃. Compressibility of the two nanocrystalline Fe3AI materials increases with the hot pressing times. Grain size of the nanocrystalline Fe3 Al materials with 10%Cr element at 600℃ and 10% Ni element at 1000℃ increases with hot pressing times, but the hardness changes little.