Implementation of Direct Metal Laser Sintering (DMLS) to Manufacture Monel K500 Liquid Rocket Engine Components

ABSTRACT: Hydrocarbon Boost (HCB) is Aerojet- Rocketdyne"s technology demonstration program for the Integrated High Payoff Rocket Propulsion Technology (IHPRPT) effort. The HCB program will establish the knowledge for the first American oxygen rich staged combustion engine. LOX rich engines contain harsh environments due to cryogenic temperatures and high oxygen concentration. MonelK500 is favored as a LOX compatible alloy. Even at high pressures it will not sustain a flame in an oxygen rich environment. The HCB program"s current demonstration of the subscale LOX rich preburner is made of several K500 components. However, conventional manufacturing methods did not provide a practical means to optimize design, reduce lead time, or lower cost. Direct Metal Laser Sintering (DMLS) is an additive process capable of producing complex geometry using one method. DMLS sequentially spreads layers of powder metal and selectively melts regions defined by a 2D slice of a 3D CAD model. Theoretically any geometry can be built. Solid Concepts is one of the most technically advanced suppliers of Direct Digital Manufacturing services. Their DMLS department specializes in aerospace components and produces parts pushing the technology"s limits. Solid Concepts Phase 1 goal will assess the feasibility of implementing DMLS to manufacture MonelK500 liquid rocket engine components. BENEFIT: The ability to develop advanced liquid rocket engine (LRE) components with Direct Metal Laser Sintering (DMLS) will provide a significant increase in design freedom thereby enabling reduced weight and improved function, with minimal cost and shorter lead times to next best alternative. The capability to reduce weight, improve function is to enable better thrust to weight ratio and create a better performing rocket engine. The Hydrocarbon Boost program is developing the first American oxygen rich staged combustion engine. Material requirements are extreme and performance is paramount. Monel K500 is favored by NASA as one of the best liquid oxygen (LOX) material and the alloy performed above expectations during the initial stages of the HCB program. However, conventional manufacturing methods do not provide adequate means to produce LRE components fast, with minimal risk, and at a reasonable price. This SBIR Phase 1 project aims to investigate Monel K500 as a novel additive material. At this time it is believed K500 has never been produced via a laser based powder bed machine. The project has identified a US based company willing to produce the powder and aims to characterize additively produced Monel K500. DMLS provides a means to optimize design thereby maximizing performance, while minimizing the risk associated with manufacturing. Tangible parts can be fabricated within days. Engineering design changes can implemented, built, and experimentally tested within two weeks with little to no additional cost. The technique has no associated tooling cost making it highly beneficial to programs requiring low volume production of complex parts. This is an ideal situation when LRE components are only needed 10 to 12 times per year. Rocket Engine companies will be able to design and produce lighter weight components of increased complexity at an increased rate. This phase 1 project will develop additive K500 and establish the knowledge base establishing an industry around additive manufacturing LRE components.