SBIR-STTR Award

The designs of complex liquid rocket engine components are limited by the manufacturing processes used to build them. Traditional manufacturing processes, such as, casting or forging and machining, although capable of producing high-quality hardware, are expensive and time consuming. CalRAM, Inc. has been developing an additive manufacturing process, Electron Beam Melting (EBM) manufacturing, which can help the AFRL achieve IHPRPT’s goals. The layer-build process produces near-net shape components directly from a CAD file by melting powder with an electron beam and does NOT need tooling to manufacture “functional” hardware. The overall Phase I Objective is to demonstrate the feasibility and benefit of EBM manufacturing with respect to producibility (cost and quality), fabrication time and material properties to achieve IHPRPT goals. A shrouded titanium impeller will be EBM manufactured and spin tested to demonstrate the ability of the process to meet the IHPRPT goals. In addition, alternative materials will be explored and evaluated.

Benefit:
If the project is funded, there are four anticipated results from Phase I: 1. The successful spin test of a shrouded upper stage titanium impeller will show that EBM manufacturing can produce a complex structure capable of meeting the structural loads. In addition, the cryogenic behavior of EBM manufactured Ti will be confirmed to meet or exceed Ti-5Al-2.5Sn ELI properties. 2. Feasibility to produce EBM manufactured Alloy 625 with a uniform, dense microstructure and comparable mechanical properties to conventionally produced Alloy 625 will have been demonstrated. 3. Producibility, cost and schedule of an EBM manufactured titanium impeller that helps the AFRL meet Phase III IHPRPT goals will have been generated. 4. A path to scale up the EBM process to produce booster size components will have been laid out.

Keywords:
Electron Beam Melting, Manufacturing, Titanium Alloys, Nickel-Base Superalloys

The overall goal of the Phase II effort is to take CalRAM?s Additive Manufacturing process, based on Electron Beam Melting (EBM) technology, to the point where it is ready to fabricate titanium hardware for Liquid Rocket Engine(LRE)production. Phase II will focus on demonstrating the EBM process to produce and evaluate LRE components. In addition to the work performed on titanium alloy components, effort to develop a nickel-base alloy for use in LRE will be performed. The final Phase II activity will be focused on scaling up the process to produce larger LRE components.

Benefit:
The benefits of employing EBM fabrication for LRE components are (1) the parts can be made faster because the process is tool-less; (2) for quantities typically used in LRE manufacture, the parts are less expensive; (3) the mechanical behavior of EBM fabricated titanium meets or exceeds that fabricated by traditional manufacturing methods; (4) Since the process is tool-less, as design concepts are tested and performance validated, it is possible to immediately implement design changes. This flexibility allows for greatly reducing the development time. Development of EBM technology for DOD LRE is directly applicable to LRE used to launch commercial payloads.

Keywords:
Liquid Rocket Engines, Electron Beam Melting, Titanium, Nickel-Base Alloys, Near-Net Shape