Work

Effects of specimen size and hot isostatic pressing on high-cycle and very-high-cycle fatigue of additively manufactured Ti6Al4V

Year: 2025

Type: article

Abstract: This study investigates the effects of specimen size and hot isostatic pressing (HIP) on the high-cycle and very high-cycle fatigue (HCF and VHCF) performance of additively manufactured (AM) Ti6Al4V. Three sets of specimens were designed. Two of them had control volumes of 50 mm3 and 8294 mm3, respectively, and the third set consisted of 50 mm3 subjected to HIP treatment. The results show that as the control volume increases, fatigue performance exhibits significant size effects, with smaller specimens possessing higher fatigue strength, which gradually diminishes with the number of failure cycles increases. For the HIP-treated specimens, crack initiation is no longer dominated by AM void defects but occurs within α-phase grains. For the other two sets,a statistical analysis of the crack initiation defects reveals that, in both HCF and VHCF states, the fatigue cracks in larger specimens always originated from internal defects. The average defect sizes for the two specimen sizes were 109 μm and 54 μm, respectively. By using the probabilistc control volume model, the fatigue strength of larger specimens was predicted based on the fatigue data of smaller specimens, and the prediction was consistent with the experimental data.

Source: Journal of Materials Research and Technology

DOI: 10.1016/j.jmrt.2025.08.054

Authors: Yu Xia, Xiangnan Pan, Aiguo Zhao, Youshi Hong

Institutions: Nanjing Tech University, Chinese Academy of Sciences, Institute of Mechanics, State Key Laboratory of Nonlinear Mechanics

Language: English

Topic: Fatigue and fracture mechanics

Subfield: Mechanics of Materials

Field: Engineering

Domain: Physical Sciences

SDG: Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $1,640