The topic of sustainable machining has in recent times emerged as a significant and impactful area of research focus as it directly deals with environmental health and protection, economic growth and prosperity, and societal wellbeing with greater health and wellness. More specifically, sustainable machining at product, process, and system levels deals with reducing negative environmental impact, offering improved energy and resource efficiency, generating a minimum quantity of wastes, providing operational safety, and offering improved personal health. This paper summarizes recent efforts by the world research community in sustainable machining with a systematic approach for the analysis of machining processes that are broadly classified as sustainable, beginning with dry machining, and then near-dry (also known as minimum quantity lubrication (MQL)) and cryogenic machining processes. The paper also extends its analysis to a hybrid mode of sustainable machining that effectively combines cryogenic and MQL machining processes for improved productivity and machining performance. While a significant part of this paper presents experimental analysis, the progress being made in modeling and optimization has also been discussed in the paper. In particular, major challenges involved in model development for practical implementation, with a view to selecting optimum cutting conditions and cutting tool selection, are primarily discussed in the paper. The need for continued modeling efforts for achieving deployable optimized conditions for sustainable machining is highly recognized, and further research is required in numerous fronts integrating the various convergent disciplines such as materials, mechanics, computational sciences, economics, environmental sciences.

This paper presents a review of recent advances in modeling and simulation of conventional metal machining processes, which continue to dominate a significant part of all machining processes, and in recent years, the need for predictive models for machining processes has grown in importance in the digital manufacturing age. Significant advances have been made in modeling the mechanics of cutting in conventional machining, driven by industrial need and enabled by rapid advances in computational power. The paper surveys the state-of-the-art in analytical and numerical modeling of conventional metal machining processes with a focus on their ability to predict useful performance attributes including chip geometry, forces, temperatures, tool wear, residual stress, and microstructure. Also included in the review is a discussion of the industrial use of modeling and simulation tools for conventional machining. Additionally, the practical applicability, implementation benefits, and methodological limitations of conventional machining process modeling have been examined. The paper concludes with a summary of future research directions in modeling and simulation of conventional metal machining processes.

Burnishing has been increasingly utilized to improve the surface integrity of manufactured components. The generation of surface and subsurface layers with ultrafine grains, attributed to severe plastic deformation (SPD) and dynamic recrystallization (DRX), leads to improved surface integrity characteristics including surface and subsurface hardness and reduction in surface roughness. Additionally, due to the generation of compressive stresses within the refined layers, increase in fatigue life and improved wear and corrosion resistance can be achieved. In this study, we apply cryogenic burnishing on Al 7050-T7451 discs and compare the surface integrity characteristics with dry conventional burnishing. A special roller burnishing tool with flexible rotating roller head was designed and used to perform the cryogenic burnishing experiments using liquid nitrogen as the coolant. The results show that cryogenic burnishing can increase the surface hardness by an average of 20–30% within a layer depth of 200 µm compared with only 5–10% increase using dry conventional burnishing. Refined layers with nano grain structure were also generated. During cryogenic burnishing, the tangential burnishing forces were higher than those of dry conventional burnishing due to rapid cooling and work hardening of the material.