A Cradle to Gate Approach for Life-Cycle-Assessment of Blisk Manufacturing

The aviation industry has been growing continuously over the past decades. Despite the current Covid-19 crisis, this trend is likely to resume in the near future. On an international level, initiatives like the Green Recovery Plan promoted by the European Union set the basis towards a more environmentally friendly future approach for the aero-industry. The increasing air traffic and the focus on a more sustainable industry as a whole lead to an extensive need for a more balanced assessment of a products life cycle especially on an ecological level. Blisks (or IBRs) remain a central component of every current and very possible every future aero engine configuration. Their advantages during operation compared to conventional compressor rotors are met with a considerably complex manufacturing and production process. In the high-pressure compressor segment of an engine, the material selection is limited to Titanium alloys such as Ti6Al4V and heat-resistant Nickel-alloys such as Inconel718. The corresponding process chains consist of numerous different process steps starting with the initial raw material extraction and ending with the quality assurance (cradle to gate). Especially the central milling process requires a highly qualified process design to ensure a part of sufficient quality. Life-Cycle-Assessments enable an investigation of a products overall environmental impact and ecological footprint throughout its distinct life-cycle. Formal LCAs are generally divided by international standards into four separate steps of analysis: the goal and scope definition, the acquisition of Life Cycle-Inventory, the Life-Cycle-Impact-Assessment and the interpretation. This content of this paper focuses on a general approach for Life-Cycle-Assessment for Blisk manufacturing. Firstly, the goal and scope is set by presenting three separate process chain scenarios for Blisk manufacturing, which mainly differ in terms of raw material selection and individual process selections for blade manufacturing. Secondly, the LCI data (Life-Cycle Inventory) acquisition is illustrated by defining all significant in- and outputs of each individual process step. Thirdly, the approach of a Life-Cycle-Impact-Assessment is presented by introducing the modelling approach in an LCA-software environment. Fourthly, an outlook and discussion on relevant impact-indicators for a subsequent interpretation of future results are conducted.