Enhancing surface integrity using a hybrid process combining simultaneous grinding and burnishing

Grinding is an abrasive machining process known for its high precision and excellent surface finish results. However, despite its effectiveness, it often faces limitations in time and energy efficiency, especially when multiple finishing passes are required. The unpredictability of these passes has led many manufacturers to integrate burnishing to erase completely or partially the microscopic peaks left by the grinding wheel. This paper presents an innovative hybrid approach that combines simultaneous grinding and burnishing to overcome these challenges. This non-conventional process offers improved surface integrity compared to performing grinding and burnishing independently. The study examines the effects of this novel process on the surface and subsurface characteristics of metallic workpieces through experimental analysis. The results demonstrate that simultaneous grinding and ball burnishing generate a thick subsurface layer with compressive residual stresses and significantly enhanced surface roughness. This process capitalizes on the changes induced by the thermomechanical grinding process, occurring short time before burnishing. Additionally, the synchronous execution of grinding and burnishing reduces energy consumption, time, and production costs. This research highlights the potential of combining thermomechanical and mechanical processes to improve surface integrity, leading to enhanced wear resistance, fatigue strength, and overall durability of workpieces. It also suggests that this approach can contribute to more eco-friendly and cost-effective manufacturing solutions.