New technology for fast casing manufacture

The investment cast Titanium intermediate casing is the major structural component in some large gas turbines, locating shafts, compressor, internal gearbox and radial drive for accessory power offtake. It is longest leadtime component during the development programme of a new engine with the definition frozen very early in the cycle to enable tooling design and procurement. A new process being developed by Rolls-Royce, based around the build-up of material from weld beads in 3D space is described which could mean a substantial reduction in the lead time for the development of such casings. By eliminating casting tooling the design can evolve for a longer time while prototypes are made, and late change can be accommodated with ease. When a stable design has been achieved a "right first time" casing can be manufactured.