A Low-Cost Method for Coating of Selective Laser Melting (SLM) Manufacturing of Complex High-Precision Components for Spaceflight Applications Using Atomic Layer Deposition (ALD)

This proposal is intended to perform basic research using Atomic Layer Deposition (ALD) as a means of coating various substrate materials with a variety of metallic and ceramic oxides for corrosion and thermal protection. In particular, due to growing interest in significant cost-reduction using the technology of Selective Laser Melting (SLM), this proposal will attempt to develop a state-of-the-art and low-cost method of polishing and coating a sub-scale thruster nozzle modeled after the ALCOT Thruster and built using SLM. SLM has shown the potential to reduce production costs by 70% or more. By combining SLM with the process of electro-polishing and application of uniform thin-film coatings using ALD, we believe that we can develop a complete manufacturing process by-which high-precision, complex and here-to-fore costly components can be produced at a fraction of their current cost. We intend to demonstrate a method of coating stainless steel, Tungsten and ultimately a Tungsten/Titanium Carbide (W/TiC) matrix created via SLM with Iridium Oxide (IrO2 or IrO3) in Phase I and Yittria-stabilized zirconia (YSZ: Y2O3-ZrO2) and Yittria (Y2O3) in Phase II. This proposal will be a demonstration of smoothing and coating several different substrate materials with a variety of oxides in Phase I which appear to offer significant benefits to the low-cost manufacture of material components of great interest to NASA.