A pathway to improve low-cycle fatigue life of face-centered cubic metals via grain boundary engineering

Abstract

• Grain boundary engineering (GBE) is a pathway to improve low-cycle fatigue life of FCC metals. • GBE significantly suppresses cyclic strain localization and cracking at GBs especially at increased stress amplitude. • The sensitivity of fatigue life to stress amplitude can be weakened by GBE. To probe a pathway to improve the low-cycle fatigue life of face-centered cubic (FCC) metals via grain boundary engineering (GBE), the tension-tension fatigue tests were carried out on the non-GBE and GBE Cu-16 at.%Al alloys at relatively high stress amplitudes. The results indicate that the cyclic strain localization and cracking at grain boundaries (GBs) can be effectively suppressed, especially at increased stress amplitude, by an appropriate GBE treatment that can result in a higher resistance to GB cracking and a greater capability of compatible deformation. Therefore, the sensitivity of fatigue life to stress amplitude can be weakened by GBE, and the low-cycle fatigue life of Cu-16 at.%Al alloys is thus distinctly improved.