TY - JOUR
T1 - Fusion defects-induced enhancement of fatigue life at elevated temperature of CoCrFeNiMo0.5 alloy produced by laser-powder bed fusion
AU - Tong, Shuai
AU - Xiong, Junming
AU - Ma, Zhichao
AU - Li, Chaofan
AU - Li, Jiakai
AU - Zhao, Hongwei
AU - Ren, Luquan
AU - Yan, Chuliang
N1 - Publisher Copyright:
© 2025 The Authors.
PY - 2025/11/1
Y1 - 2025/11/1
N2 - The inherent porosity in additive manufacturing is typically classified as fusion-related defects, and the low cycle fatigue (LCF) life of most metallic materials diminishes with increasing temperature. Notably, the CoCrFeNiMo0.5 alloy containing fusion defects exhibited an anomalously enhanced LCF life at elevated temperatures compared to ambient conditions. Utilizing a custom-designed mechanical-thermal coupling fatigue testing apparatus, we conducted LCF assessments of the CoCrFeNiMo0.5 alloy across a temperature spectrum from 20 °C to 600 °C. Specimens fabricated with three different laser power settings demonstrated increased fatigue life at 200 °C, with the specimen processed at 165 W laser power showing a 65.6 % improvement in LCF life at 200 °C relative to room temperature. Microstructural analysis across multiple scales revealed that porosity acts as a stress dissipation mechanism, mitigating localized stress concentrations, thereby retarding crack initiation and propagation, and ultimately extending fatigue life.
AB - The inherent porosity in additive manufacturing is typically classified as fusion-related defects, and the low cycle fatigue (LCF) life of most metallic materials diminishes with increasing temperature. Notably, the CoCrFeNiMo0.5 alloy containing fusion defects exhibited an anomalously enhanced LCF life at elevated temperatures compared to ambient conditions. Utilizing a custom-designed mechanical-thermal coupling fatigue testing apparatus, we conducted LCF assessments of the CoCrFeNiMo0.5 alloy across a temperature spectrum from 20 °C to 600 °C. Specimens fabricated with three different laser power settings demonstrated increased fatigue life at 200 °C, with the specimen processed at 165 W laser power showing a 65.6 % improvement in LCF life at 200 °C relative to room temperature. Microstructural analysis across multiple scales revealed that porosity acts as a stress dissipation mechanism, mitigating localized stress concentrations, thereby retarding crack initiation and propagation, and ultimately extending fatigue life.
KW - Fatigue life enhancement
KW - High entropy alloys
KW - Laser-powder bed fusion
KW - Local stress dissipation
KW - Mechanical-thermal coupling
UR - https://www.scopus.com/pages/publications/105021223344
U2 - 10.1016/j.jmrt.2025.09.134
DO - 10.1016/j.jmrt.2025.09.134
M3 - 文章
AN - SCOPUS:105021223344
SN - 2238-7854
VL - 39
SP - 1159
EP - 1167
JO - Journal of Materials Research and Technology
JF - Journal of Materials Research and Technology
ER -