Life Cycle Assessment - a Comparison of Various Thermal Spray Processes and Electroplating

The environmental strategies of European Union on resources and wastes are based on lifecycle thinking. In surface finishing, they encourage the substitution of conventional wet deposition processes that involve chemicals and effluents by “dry” processes, such as thermal spraying. However, all metal finishing processes have certain impacts on human health, ecosystems, and resources. The life cycle assessment (LCA) methodology is internationally used for identifying, comparing and reducing the environmental impacts of processes and products. It requires quantifying the resources used (materials and energy) and emissions (solid, liquid and gaseous wastes) at all stages of the process (raw materials extraction, manufacturing, use and end-of-life).

This study is an LCA comparison of various thermal spray processes (plasma spraying, twin-wire arc spraying, and cold spray) and electroplating for the formation of nickel coatings. It was done using a peer-reviewed database of upstream materials and energy (EcoInvent), and the LCA program SimaPro (Eco-Indicators-99). The uses of materials and energy, and the corresponding emissions of each coating process, were converted to impact scores to human health, ecosystems, and resource depletion (fossil and mineral resources).