Metal AM Replaces Castings

GE engineers switched four existing parts from castings to metal 3D printing and see potential for hundreds more as AM competes with casting on cost alone.

Most manufacturers would never dream of switching an existing part from an investment casting to one made by metal AM.  But that is exactly what GE Aviation engineers are doing with four bleed air parts for a turbine engine. The decision was based on cost and time-to-market, even though the casting molds were already made.

The engineering team from GE Aviation and GE Additive expect its four AM parts will reduce part cost by up to 35%. More importantly, the conversion process took only 10 months to go from identifying parts to final AM prototypes. Typical aerospace cast turbine parts require 12 to 18 months.

This is just the beginning. The project has identified dozens of other parts on a variety of engines that they could convert to AM and save time and money. AM is perfect for making complex parts, especially those with internal channels. Additive also works well for parts with simple geometries as they eliminate the up-front time and investment in molds or tooling needed for casting.

The parts were all made of CoCr, an alloy widely used for hot-turbine parts. All four parts are about 3.5 inches in diameter and about six inches tall. They would be made of CoCr to handle the hot compressed air from the turbine’s compressor section.