Wang Guanyi, Che Xin, Zhang Zhipeng, Zhang Haoyu, Zhang Siqian, Li Zhengyuan, Sun Jie
School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, China.
State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China.
Materials (Basel). 2020 Jan 31;13(3):638. doi: 10.3390/ma13030638.
The low-cycle fatigue behavior of Al-9Si-4Cu-0.4Mg-0.3Sc alloy with different casting states was investigated by performing low-cycle fatigue tests and by means of observations and analysis with a scanning electron microscope (SEM) and a transmission electron microscope (TEM). It was found that the metal-mold cast and die-cast Al-9Si-4Cu-0.4Mg-0.3Sc alloys exhibited the cyclic stress response of strain hardening under all imposed total strain amplitudes. The cyclic deformation resistance and fatigue life of the metal-mold cast Al-9Si-4Cu-0.4Mg-0.3Sc alloy were lower than those of the die-cast Al-9Si-4Cu-0.4Mg-0.3Sc alloy. The plastic strain and elastic strain amplitudes of the metal-mold cast and die-cast Al-9Si-4Cu-0.4Mg-0.3Sc alloys were linearly related to the number of reversals to failure, which obeyed the Coffin-Manson and Basquin formulas, respectively. The results of TEM observation revealed that at all imposed total strain amplitudes, the cyclic deformation mechanisms of the metal-mold cast and die-cast Al-9Si-4Cu-0.4Mg-0.3Sc alloys were planar slip and wavy slip at the lower and higher strain amplitudes, respectively.
通过进行低周疲劳试验，并借助扫描电子显微镜（SEM）和透射电子显微镜（TEM）进行观察与分析，研究了不同铸造状态的Al-9Si-4Cu-0.4Mg-0.3Sc合金的低周疲劳行为。结果发现，金属模铸造和压铸的Al-9Si-4Cu-0.4Mg-0.3Sc合金在所有施加的总应变幅值下均表现出应变硬化的循环应力响应。金属模铸造的Al-9Si-4Cu-0.4Mg-0.3Sc合金的循环变形抗力和疲劳寿命低于压铸的Al-9Si-4Cu-0.4Mg-0.3Sc合金。金属模铸造和压铸的Al-9Si-4Cu-0.4Mg-0.3Sc合金的塑性应变幅值和弹性应变幅值分别与失效反向次数呈线性关系，分别符合科芬-曼森公式和巴斯奎因公式。TEM观察结果表明，在所有施加的总应变幅值下，金属模铸造和压铸的Al-9Si-4Cu-0.4Mg-0.3Sc合金的循环变形机制在较低应变幅值下分别为平面滑移和在较高应变幅值下为波浪状滑移。
