Approach to sustainability evaluation and optimization of machining parameters in the turning process of AISI 304 steel

The study investigates the sustainability evaluation and optimization of machining parameters in the turning process of AISI 304 steel under different lubrication and cooling conditions. The research employs a Taguchi experimental design to assess the impact of various cutting parameters, comparing dry cutting with a hybrid semi-dry method using CO2 and Minimum Quantity Lubrication (MQL) with nano TiO2. The optimization of the process resulted in Vc of 195 m/min and f of 0.2 mm/rev cutting conditions. The findings demonstrate that hybrid lubrication and cooling significantly reduce tool wear and extend tool life compared to dry cutting (80% better). The type of cutting fluid is identified as the most critical factor in prolonging tool life resulting the Cryo + MQL + nano TiO2 better than dry conditions. In the sustainability analysis, the Grey Relational Analysis (GRA) method was used. Encompassing economic, environmental, and social indicators, the study reveals that hybrid machining processes (GRG: 0.61) could be one of the alternatives to be used in terms of energy consumption tool life, and environmental impact for its behaviour to replace dry machining (GRG: 0.83). This study provides a comprehensive framework for optimizing machining processes with a focus on sustainability, highlighting the benefits of hybrid lubrication and cooling systems in improving tool performance and reducing environmental impact.