Issue 57

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

particles addition and the heat treatment. Besides, as it was reported in the literature [22,23], a higher value of mean stress has resulted in higher responded plastic strain amplitude and also a higher rate of cyclic hardening in the case of AlSi alloys and a higher rate of cyclic softening in the case of AlSi_N_T6.

Figure 12: Tensile flow curves of AlSi and AlSi_N_T6.

AlSi

AlSi_N_T6 70.53 ± 7.60 99.12 ± 6.96 224.40 ± 10.20

85.55 ± 6.26

Elastic modulus ( GPa ) Yield stress ( MPa ) Ultimate stress ( MPa )

105.93 ± 10.03 236.67 ± 16.21

Elongation ( % ) 3.69 ± 0.21 Table 5: Mechanical properties of AlSi and AlSi_N_T6. 1.51 ± 0.23

Figure 13: First and mid-life hysteresis loops of AlSi and AlSi_N_T6 under the stress amplitude of 200 MPa , the stress rate of 100 MPa/s and the mean stress of 0 MPa .

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