The fatigue damages due to pores of MIM-sintered Ti64 were investigated using the synchrotron X-ray CT imaging. The effect of pores on the fatigue strength limits was analysed independently from that of grain size by introducing the fatigue limit ratio R_F. The pores near to the maximum-stress area were identified by elastic FEM. The maximum stress intensity factor K_I-max at the edge of the identified pores showed a negative correlation with R_F. Moreover, the initial cleavage in the crack was influenced by the mutual interference of both stress fields by the proximity of the identified pore and its adjacent pores.

中文翻译：

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定量估计孔径和最近邻孔之间的距离对 Ti-6Al-4V MIM 烧结材料中高周疲劳 (HCF) 裂纹萌生的贡献

使用同步加速器 X 射线 CT 成像研究了 MIM 烧结 Ti64 的孔隙引起的疲劳损伤。通过引入疲劳极限比R _F，气孔对疲劳强度极限的影响独立于晶粒尺寸进行了分析。通过弹性有限元法识别最大应力区域附近的孔隙。已识别孔隙边缘的最大应力强度因子K _{I - max}与R _F呈负相关。此外，裂纹中的初始解理受到已识别孔隙及其相邻孔隙的接近引起的两个应力场的相互干扰的影响。