Sustainable Machining of Aerospace Alloys for Improved Product and Process Sustainability: Evaluation of Dry, Near-dry (MQL) and Cryogenic Machining Processes

When evaluating the sustainability of a machining process, the effects on the product sustainability cannot be neglected. A more sustainable process cannot generate a less competitive product or a less sustainable one. This aspect has to be considered when planning changes in the manufacturing process which also affect the product. It is crucial to contemporarily evaluate the sustainability of the process and the product. This problem become more severe when manufacturing of aerospace components that need to satisfy high quality standards for the product performance. In this context, surface integrity plays a key role because it dictates the functional performance and service-life of engineered components. Hence, knowledge about factors that cause microstructural improvements will contribute to a better fundamental understanding of the manufacturing process mechanics and improved knowledge-driven manufacturing process planning. The scope of this research is to evaluate the process/product sustainability performance for aluminum AA7075-T651 and Titanium Ti6Al4V alloys and the major objectives are: -Improve the process sustainability performance by improving the environmental impact in terms of hazard, energy consumption and tool wear; -Investigating the influence of processing conditions, especially the use of different cooling/lubrication methods, on surface integrity changes such as microstructure, hardness modification, phase changes etc. generated by machining; -Evaluating the resulting product performance of machined samples in terms of fatigue life; -Developing a customized numerical model to predict material flow stress changes, grain size refinement, and hardness modification, in the machined surface and sub-surface under different processing conditions; -Optimize the process in order to evaluate the overall sustainability