Additive Manufacturing of Liquid Rocket Engine Combustion Devices: A Summary of Process Developments and Hot-Fire Testing Results

Abstract

Additive Manufacturing (AM) of metals is a processing technology that has significantly matured over the last decade. For liquid propellant rocket engines, the advantages of AM for replacing conventional manufacturing of complicated and expensive metallic components and assemblies are very attractive. AM can significantly reduce hardware cost, shorten fabrication schedules, increase reliability by reducing the number of joints, and improve hardware performance by allowing fabrication of designs not feasible by conventional means. The NASA Marshall Space Flight Center (MSFC) has been involved with various forms of metallic additive manufacturing for use in liquid rocket engine component design, development, and testing since 2010. The AM technique most often used at the NASA MSFC has been powder-bed fusion or selective laser melting (SLM), although other techniques including laser directed energy deposition (DED), arc-based deposition, and laser-wire cladding techniques have also been used to develop several components. The purpose of this paper is to discuss the various internal programs at the NASA MSFC using AM to develop combustion devices hardware. To date at the NASA MSFC, combustion devices component hardware ranging in size from 100 lbf to 35,000 lbf have been designed and manufactured using SLM and deposition-based AM processes, and many of these pieces have been hot-fire tested. Combustion devices component hardware have included thrust chamber injectors, injector components such as faceplates, regeneratively-cooled combustion chambers, regeneratively-cooled nozzles, gas generator and preburner hardware, and augmented spark igniters. Ongoing and future developments for combustion devices have also included design of components sized for boost-class engines. Several design and hot-fire test iterations have been completed on these subscale and larger scale components, and a summary of these results will be presented as well.

Study on the Effects of Different Cutting Angles on the End-Milling of Wire and Arc Additive Manufacturing Inconel 718 Workpieces

“…For instance, when it comes to the microstructure, it was already informed that the WAAM samples are composed of dendrite formations, this kind of microstructure has also been reported to have different diameters throughout the three axes, ranging from sizes as small as 53 µm to as big as 615 µm [ 9 ]. As stated previously, this could be another influence for the differences found in the cutting force values.…”

“…In contrast to the previously mentioned advantages, due to the deformations caused by high heat input, the quality of the surfaces being manufactured with WAAM is not suitable for most final products; with that, a post-processing step is required [ 6 ]. Notwithstanding, even with the difficulties of manufacturing with a relatively novel technique, new examples of products being produced with the WAAM method are surging, ranging from marine propellers [ 7 ] and aeronautical structural panels [ 8 ] to rocket engine combustion systems [ 9 ]. Based on the type of use and consequently necessary required properties of materials like aluminum, copper, titanium and nickel alloys are employed for metal additive manufacturing.…”

Layer-by-layer generation of optimized joint trajectory for multi-axis robotized additive manufacturing of parts of revolution

“…Industrial applications related to this work are mainly related to the aerospace field, as for the manufacture of rocket nozzles [60,61], fuel tanks or pressure vessels.…”

GRCop-42 Development and Hot-fire Testing Using Additive Manufacturing Powder Bed Fusion for Channel-cooled Combustion Chambers

“…A standard slip-jacket chamber was baselined for the test program. A SLM GRCop-84 liner was previously tested in an identical configuration using various propellants and provided a good baseline for the GRCop-42 liner 24 . The goal of this GRCop-42 liner testing was to accumulate multiple duty cycles (high number of starts and seconds) to demonstrate the feasibility of the GRCop-42 material in a high heat flux environment.…”