You may want to take a look at GE's 3-D printing sites on the internet. For example, the new GE90X engine for the Boeing 777X contains numerous 3-D printed parts including 3-D printed LPT blades. The engine has passed its initial certification to enable full flight testing this year. GE bought a company in Italy that developed the machines and processes for producing larger components such as the GE90X LPT blades now being produced. The developed processes have the same capability to produce LPT blades as rapidly as if they were cast, but with much more in terms of initial design freedoms.