Due to the defects, the performance of laser directed energy deposition (LDED) parts was restricted. This work investigated the strain-controlled high-temperature fatigue behavior of LDED Hastelloy X after ultrasonic micro-forging treatment (UMFT). Results showed that UMFT significantly increased the fatigue life twice; mathematical statistical analysis showed that the size of the fatigue source (defect) and the fatigue loading conditions accounted for the fatigue lifetime of the LDED Hastelloy X; based on the organic combination of Smith-Watson-Topper (SWT) and Stress intensity factor (SIF) models, a new defect-related strain-controlled fatigue life prediction model was proposed with the correlation coefficient of 0.93.

由于缺陷，激光定向能量沉积（LDED）部件的性能受到限制。这项工作研究了超声微锻造处理 (UMFT) 后 LDED 哈氏合金 X 的应变控制高温疲劳行为。结果表明，UMFT显着提高了疲劳寿命两倍；数理统计分析表明，疲劳源（缺陷）的大小和疲劳加载条件对LDED Hastelloy X的疲劳寿命有影响；基于Smith-Watson-Topper（SWT）和应力强度因子（SIF）模型的有机结合，提出了一种新的缺陷相关应变控制疲劳寿命预测模型，相关系数为0.93。