多轴载荷下ZL101铝合金的低周疲劳行为

研究不同等效应变幅下ZL101铝合金在多轴比例和非比例载荷下的低周疲劳行为,并用透射电镜观察合金的疲劳行为中的位错结构。结果表明：合金在两种加载方式下均表现为循环硬化;在非比例载荷下合金表现出附加强化,但程度不明显;合金的疲劳寿命随等效应变幅的增加而降低,合金在非比例加载下的疲劳寿命低于比例加载时的疲劳寿命。对位错结构的观察表明,随等效应变幅度的提高,合金的低周疲劳位错结构从交叉位错带转化为位错胞,合金在非比例加载下更易形成位错胞结构。

Low cycle fatigue behavior of cast aluminum alloy ZL101 under multi-axial loading

Multi-axial low cycle fatigue behavior of cast aluminum alloys ZL101 at different equivalent strain ranges under proportional and non-proportional loadings were studied, the dislocation substructures of ZL 101 were observed by TEM. The results show that the aluminum alloy shows cyclic hardening both under multi-axial proportional and non-proportional loadings, while the cyclic additional hardening is shown under non-proportional loading, but the level is low. The multi-axial fatigue life decreases as the equivalent strain amplitude increases under both of multi-axial loadings. The fatigue life under non-proportional loading is less than that under proportional loading at the same equivalent strain amplitude. The deformation substructure examination reveals that with increasing equivalent strain amplitude, the dislocation structure tends to change from cross dislocation bands to dislocation cells. It is easier to form dislocation ceils under non-proportional loading.