Nečemer Branko, Zupanič Franc, Vuherer Tomaž, Glodež Srečko
Faculty of Mechanical Engineering, University of Maribor, Smetanova 17, 2000 Maribor, Slovenia.
Materials (Basel). 2023 Mar 28;16(7):2674. doi: 10.3390/ma16072674.
This study presents a comprehensive experimental investigation of the high-cycle fatigue (HCF) behaviour of the ductile aluminium alloy AA 5083-H111. The analysed specimens were fabricated in the rolling direction (RD) and transverse direction (TD). The HCF tests were performed in a load control (load ratio = 0.1) at different loading levels under the loading frequency of 66 Hz up to the final failure of the specimen. The experimental results have shown that the S-N curves of the analysed Al-alloy consist of two linear curves with different slopes. Furthermore, RD-specimens demonstrated longer fatigue life if compared to TD-specimens. This difference was about 25% at the amplitude stress 65 MPa, where the average fatigue lives 276,551 cycles for RD-specimens, and 206,727 cycles for TD-specimens were obtained. Similar behaviour was also found for the lower amplitude stresses and fatigue lives between 10 and 10 cycles. The difference can be caused by large Al(Mn,Fe) particles which are elongated in the rolling direction and cause higher stress concentrations in the case of TD-specimens. The micrography of the fractured surfaces has shown that the fracture characteristics were typical for the ductile materials and were similar for both specimen orientations.
本研究对韧性铝合金AA 5083-H111的高周疲劳（HCF）行为进行了全面的实验研究。所分析的试样是沿轧制方向（RD）和横向（TD）制备的。高周疲劳试验在载荷控制（载荷比 = 0.1）下，于不同载荷水平、66 Hz的加载频率下进行，直至试样最终失效。实验结果表明，所分析铝合金的S-N曲线由两条斜率不同的线性曲线组成。此外，与横向试样相比，轧制方向试样的疲劳寿命更长。在65 MPa的应力幅值下，这种差异约为25%，此时轧制方向试样的平均疲劳寿命为276,551次循环，横向试样为206,727次循环。在10至10次循环之间的较低应力幅值和疲劳寿命情况下也发现了类似的现象。这种差异可能是由沿轧制方向拉长的粗大Al(Mn,Fe)颗粒引起的，在横向试样中会导致更高的应力集中。断口表面的显微照片表明，断裂特征对于韧性材料来说是典型的，并且两种试样取向的情况相似。
