钼对Fe_3Al基合金力学性能的影响

Effect of Molybdenum on the Mechanical Properties of Fe_3Al-Based Alloys

Ｍｏ对改善Ｆｅ２Ａｌ的高温力学性能有十分重要的作用。在Ｆｅ－２８Ａｌ－５Ｃｒ合金中，Ｍｏ的溶解度在１％（ｍｏｌ／ｍｏｌ）左右。Ｍｏ含量超过１％时，基体中有富Ｍｏ的第二相颗粒形成。Ｍｏ的加入提高了合金的室温和高温强度，改善了抗蠕变性能，并使Ｆｅ３Ａｌ的屈服强度和温度反常关系中的强度峰向高温方向移动。但是Ｍｏ加入Ｆｅ３Ａｌ后导致塑性降低，并提高了合金的脆性转变温度，这对热形变加工带来不利的影响。

Molybdenum plays an important role in improving mechanical properties of Fe3Al at high temperature.The solubility of Mo is about 1 at.% in the Fe-28Al-5Cr alloy. If the amount of the Mo addition is more than 1 at.%,the second phase particles form in the matrix.The Mo addition to Fe3Al increases strength at both of room and high temperatures,improves creep resistance and moves the strength peak in the anomalous curve of yield strength versus temperature towards the higher temperature side.However,Mo addition to Fe3Al results in the decrease of ductility and increase of the brittle transition temperature,and this brings disadvantageous effects on deformation processing of Fe3Al alloys.