Defect extreme value analysis and fatigue life prediction model for SLM-manufactured TiB2-Al and TC4 alloys

[Display omitted] •High cycle fatigue tests are conducted on SLM-manufactured TiB2-Al alloy and TC4 alloy.•Metallographic experiment measures the micropore defects of materials.•Large-scale defects have significant effect on crack propagation and fatigue life.•The Peaks Over Threshold (POT) method is employed in defect extreme value analysis (EVA).•The fatigue life prediction model is established based on finite element simulation and EVA analysis. Selective Laser Melting (SLM) technology is increasingly employed in the manufacturing of complex components, offering significant design flexibility. The presence of large defects originating from the casting process severely impacts the fatigue performance of SLM-fabricated structures. This paper utilizes the Peak Over Threshold (POT) method and Poisson distribution to investigate the distribution patterns of large-scale defects. A fatigue life prediction model is established, incorporating the probability of large-scale defect occurrence across different stress regions. High cycle vibration tests and metallographic analysis are performed to evaluate the fatigue life and defect characteristics of the specimens. The results demonstrate that most fatigue data points fall within the predicted fatigue dispersion zone, validating the reliability of the proposed fatigue life model.