An empirical bi-parametric model based on the Vickers hardness HV and a proper microstructural length parameter, l, was proposed to estimate the fully reversed threshold-Stress Intensity Factor for long cracks of wrought and additively manufactured (AM) alloys. In this paper, the model has been extended to positive load ratios (R ≅ 0 and ≅ 0.5). Afterwards, experimental results generated from testing AM specimens containing natural defects were taken from the literature and were compared successfully with the estimation based on the El Haddad Smith Topper and the Atzori Lazzarin Meneghetti models defined solely on the basis of the HV and l.

提出了一种基于维氏硬度 HV 和适当的显微结构长度参数l的经验双参数模型，以估计锻造和增材制造 (AM) 合金长裂纹的完全反向阈值应力强度因子。在本文中，该模型已扩展到正载荷比（R ≅ 0 和 ≅ 0.5）。之后，从文献中提取包含自然缺陷的 AM 试样测试产生的实验结果，并成功地与基于 El Haddad Smith Topper 和 Atzori Lazzarin Meneghetti 模型的估计结果进行比较，这些模型完全基于 HV 和l 定义。