Sustainability in manufacturing processes: Finding the environmental impacts of friction stir processing of pure magnesium

Manufacturing activities consume a significant share of energy and natural resources and create some irreversible environmental impacts leading to climate change. A recent report from IPCC has highlighted the seriousness of global climate change. To mitigate the environmental burdens from manufacturing activities, it is necessary to identify and visualize them. Tools based on life cycle assessment (LCA) method have proven capabilities to visualize the hotspots during different stages of product life cycle and to support decision-making. This paper presents friction stir processing (FSP) of pure magnesium for bio implants and its environmental impact assessment in the Indian context. The study is aimed to visualize the FSP of pure Mg and major hotspots in the process to improve sustainability. The primary data for the inventory analysis was collected using real-time observations during each step of the process; whereas for secondary data, product catalogs and reports were utilized. The analysis shows that the production process of magnesium and energy used during electric discharge machining (EDM) have the highest environmental impacts. Additionally, in magnesium production, the direct emissions generated due to the burning of fossil fuel are the major contributors to these impacts. The steel used for FSP tool production and brass wire used in EDM for sizing of the magnesium plates, are also found to be contributing significantly toward water depletion potential. The study provides a conceptual approach including possible technological interventions to improve the process sustainability. The study suggests adopting advanced technologies of practical significance like 'zinc coated cutting wires' for improving the environmental performance of the process. (c) 2020 CIRP.