MTU Aero Engines produces parts by additive manufacturing

Additive manufacturing technology is rapidly spreading from one industry sector to the next. In the field of aero engine construction, Munich-based MTU Aero Engines has achieved a breakthrough: As one of the first companies to use the new technique, MTU produced components for production engines this past May. These parts – borescope bosses for the PurePower PW1100G-JM engine, the Pratt & Whitney engine to power the A320neo – are made by selective laser melting, or SLM. The low-pressure turbine for the PW1100G-JM geared turbofan (GTF) engine will be the first turbine ever to come equipped with borescope bosses produced by additive manufacturing processes. The bosses form part of the turbine case and allow the blading to be inspected at specified intervals for wear and damage using a borescope. “We used to make these parts by casting or by milling them from the solid,” explains Martens. Now they are being manufactured by SLM. With this technique, the first step is to slice up a 3D CAD model of the component to be produced. A laser then builds up the solid equivalent of the model layer by layer from a powdered material, the layer thickness being 20 to 40 micrometers. The powder particles are locally melted and fused together. At the moment, the borescope bosses are still being produced in small quantities only. Things will be different from 2015 on: Once production of the PW1100G-JM engine to power the A320neo ramps up, MTU’s production volumes, too, will go up substantially.