Issue 57

A. Basiri et alii, Frattura ed Integrità Strutturale, 57 (2021) 373-397; DOI: 10.3221/IGF-ESIS.57.27

strain increases in the case of AlSi alloys but after nano-particles and the heat treatment, the mean strain tends to move toward the compressive region as the loading rate increases. Based on Figs. 24-26 and the tensile test results in Tab. 5, a verification of obtained experimental data could be reported. Since the fatigue lifetime was only some cycles (less than 10 cycles) under high stress levels, near the ultimate strength of studied materials. However, one important note is to have different material behaviors under different stress rates. In other words, tensile testing was done at a different loading rate, compared to the loading rate in LCF testing. Therefore, the results of tensile and fatigue testing could not exactly compare to each other.

Figure 20: Test results regarding the stress amplitude effect under zero mean stress and the stress rate of 100 MPa/s for evolutions of the strain amplitude over cycles for both AlSi and AlSi_N_T6.

Figure 21: Test results regarding the stress amplitude effect under zero mean stress and the stress rate of 100 MPa/s for evolutions of the plastic strain amplitude over cycles for both AlSi and AlSi_N_T6.

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