Assessment of the ecological impact of metal additive repair and refurbishment using powder bed fusion by laser beam based on a multiple case study

When a product has reached the end of its useful life, different strategies can be used to extend its lifespan. In additive manufacturing, two of these strategies are additive repair and refurbishment, which aim to recover or improve a product's properties and functionality. However, it is important to consider the potential negative ecological impacts of these end-of-life strategies and how they can be implemented in an environmentally sustainable way. To address this, a generic model based on life cycle impact assessments is developed to evaluate different demonstrators. Starting from technical process chains via the integration of process- and product-specific data, different demonstrators are evaluated and compared based on a model. This paper explores previous research on additive repair and remanufacturing processes and their ecological assessment. An assessment framework for MAR/R (metal additive repair/refurbishment) is presented, with a subsequent life cycle assessment (LCA) of four demonstrators. Proceeding from these results, recommendations for action are discussed for users as well as further scientific research. A result of this multi-case study is that environmental hotspots within the process chain are primarily material-dependent so the amount of metallic powder has a significant influence on the overall ecological impact. The paper concludes with recommendations for efficient use of additive repair and refurbishment. (207 words) •Innovative use of metal additive manufacturing allow new end-of-life potentials.•Material flow networks represent environmental dependencies in process chains.•Metal repair and refurbishment allow products entering another product life cycle.•Holistic evaluation in a multi-case study enables to develop expert knowledge.