SEM analysis shows that the alloy containing 1%Nd exhibits the maximum fatigue propagation regions. There exists rip edge and dimple in rupture of three different Nd content alloys,showing quasi-cleavage and toughness fracture.

• 疲劳断口SEM形貌分析表明；Nd含量为1.；13%25的合金具有最大的疲劳裂纹扩展区域；3种Nd含量的合金疲劳断口都存在撕裂棱和韧窝；表现为准解理和韧性断裂的混合特征。