Residual Stress Measurement in Diamond Burnished Aluminum Alloy: Challenges and a Numerical Solution Strategy Using Finite Element Method

According to engineering practice, fatigue failure of machine components is most frequently caused by tensile residual stresses arising at stress concentration zones, which justifies the detailed investigation and development of technologies capable of intentionally generating compressive residual stress. One of these technologies is burnishing, the effects of which are investigated using X-ray diffraction, a physical measurement method whose most significant advantage is the possibility of non-destructive material testing. However, the application of this method to aluminum and its alloys is limited due to their weak diffraction cross-section, which is further distorted by cold plastic deformation. As a possible solution to this problem, finite element modelling is applied, as it has long played an important role in the design and analysis of forming technologies. The planning and execution of the investigations are based on the full factorial experimental design method, using modern machining equipment, measuring devices, and simulation software. The results show that diamond burnishing generates substantial compressive residual stresses in tangential and axial directions, while the numerical simulations predict a compressive stress field extending to a depth of approximately 0.20 mm beneath the surface. The study not only highlights the life-enhancing effect of surface burnishing but also points out the difficulties of accurate evaluation, for which numerical simulation offers an effective solution.