Effects of Grain Boundary Misorientation Angle on the Mechanical Behavior of Al Bicrystals

Abstract

This research article explores the effect of grain boundary (GB) misorientation on the mechanical behavior of aluminum (Al) bicrystals by means of molecular dynamics (MD) simulations. The effect of GB misorientation on the mechanical properties, fracture resistance, and crack propagation are evaluated under monotonic and cyclic load conditions. The J-integral and the crack tip opening displacement (CTOD) are assessed to establish the effect of the GB misorientation angle on the fracture resistance. The simulations reveal that the misorientation angle plays a significant role in the mechanical response of Al bicrystals. The results also evidence a gradual change in the mechanical behavior from brittle to ductile as the misorientation angle is increased.

Fatigue Life Estimation Model of Repaired Components with the Expanded Stop-Hole Technique

“…Firstly, the introduction of compressive residual stresses near the notch tip during hole expansion retards crack initiation and propagation. Additionally, plastic deformation-induced changes in the microstructure of steels, such as deformationinduced martensite transformation and alterations in dislocation density, can influence the fatigue life of the components [31,32]. However, the level of success achieved with the (expanded and unexpanded) SH technique varies significantly, ranging from a modest 6% life extension [5] to a promising total fatigue life of around 10 6 cycles [19].…”