Ecological trends in machining as a key factor in sustainable production - A review

A comprehensive analysis of literature pertaining to ecological trends in machining processes of difficult-to-cut materials (e.g. hard steels, Ti-based alloys, Ni-based alloys) has been performed. The paper focuses on the improvement of machining processes with a balanced attention onthe reduction of pollution generated by coolants and emulsions. Here, the specific areas of interest are: Dry cutting; Minimum Quantity Lubrication/Minimum Quantity Cooling Lubrication; Cryogenic Cooling; High-Pressure Coolant and Biodegradable Vegetable Oils. The proposed approach of sustainable and cleaner production for the above-mentioned areas involves the minimized use of coolant/lubricants, employment of appropriate cutting tool's grade and machining conditions that leads to the reduction of total cost, cutting force, energy consumption, temperature but improvements of surface quality, volume of material removed, as well as the prolongation of tool life. In addition, the qualitative judgments like impact on human operator's health, atmospheric air, chip removal from machining area etc. are taken into account. The study presented in the paper is such a vast compendium of knowledgeregarding multi-directional critical analysis of machined parts, tools, chips under state-of-art cooling/lubrication systems that it will help the next generation scientists to find recent advances as well as future avenues of research on ecological aspects of machining for sustainability. (C) 2019 Elsevier Ltd. All rights reserved.