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Justin McElderry

Publications and source records attributed to Justin McElderry.

12 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2025

Radiation-Resistant Ti/BN Coatings: Insights From 171 Days Exposure to Space Radiation and Atomic Oxygen in Low Orbit

Atmospheric Plasma Spray (APS) and Vacuum Plasma Spray (VPS) techniques were used to develop Ti/2 vol.% hBN coatings, for extreme space environments and tested aboard the International Space Station as part of the MISSE-17 (Materials International Space Station Experiments) program. The coatings were exposed to atomic oxygen, space radiation, and low-orbit thermal cycling. VPS coatings showed a 56% increase in microhardness, a 26% rise in elastic modulus, minimal porosity and crack density changes compared to APS coatings. The change in mechanical properties is attributed to the formation of TiO, TiO₂ and TiN from nitrogen retention, alongside radiation-induced dislocations, which enhanced surface hardening. The oxidation of titanium led to the formation of TiO and TiO₂, while boron nitride was retained and underwent transmutation in VPS coatings. XPS and EDS analyses confirmed the enhanced space-environment resistance of VPS coatings, making them ideal for long-term spacecraft protection in lunar and Martian conditions.

Abhijith Kunneparambil Sukumaran↗
NASA NTRSDate not supplied

AM Powder Flowability Capabilities at NASA Marshall Space Flight Center (MSFC)

Additive Manufacturing (AM) powder flowability is critical to metal 3D printing, because the more fluid the powder is, the better powder spreads. The NASA MSFC’s Contamination Control Team (CCT) studies density, flow, particle size distribution, and morphology for programs such as Moon-to-Mars Planetary Autonomous Construction Technology (MMPACT), ASTM Proficiency Testing for AM and Powder Metallurgy, and MSFC’s AM team. Examining and measuring powder characteristics is essential for improving flowability of AM powder and ensuring lot-to-lot consistency, which will help to prevent defects in manufactured parts. The CCT uses several methods to characterize AM powder. Optical particle size distribution and morphology analyses determine particle parameters including size, circularity, convexity, and dimensions. The Carney and Hall Flowmeter Funnel measures time it takes powder to flow through a funnel to compare relative flowability (free-flowing and non-free-flowing). In addition to this, the device utilizes a density cup which determines apparent density. Lastly, the Revolution Powder Analyzer measures dynamic powder flowability and behavior over time via digital imaging. Using the CCT’s lab, the team has produced ASTM Powder Proficiency Testing results with flow rates, apparent density, particle size distribution, and tap density on titanium-based and nickel-based powder and compared data with other companies/labs. Morphology data was also collected for various regolith simulant powder for the MMPACT program. Lastly, the CCT used morphology data to examine the flowability of Inconel 718 powder for Selective Laser Melting (SLM) and Directed Energy Deposition (DED) printers at MSFC. The CCT’s essential work in studying and enabling AM powder characterization has helped and will continue to help study new and refined powders in the AM industry.

Additive Manufacturing↗
NASA NTRSDate not supplied

AM Powder Flowability Capabilities at NASA Marshall Space Flight Center (MSFC)

Additive Manufacturing (AM) powder flowability is critical to metal 3D printing, because the more fluid the powder is, the better powder spreads. AM Powder Flowability Capabilities at NASA MSFC studies density, flow, particle size distribution, and morphology for programs such as Moon-to-Mars Planetary Autonomous Construction Technology (MMPACT), ASTM Proficiency Testing for AM and Powder Metallurgy, and MSFC’s AM team. Examining and measuring powder characteristics is essential for improving flowability of AM powder and ensuring lot-to-lot consistency, which will help to prevent defects in manufactured parts. The Contamination Control Team (CCT) uses several methods to characterize AM powder. Optical particle size distribution and morphology analyses determine particle parameters including size, circularity, convexity, and dimensions. The Carney and Hall Flowmeter Funnel measures time it takes powder to flow through a funnel to compare relative flowability (free-flowing and non-free-flowing). In addition to this, the device utilizes a density cup which determines apparent density. Lastly, the Revolution Powder Analyzer measures dynamic powder flowability and behavior over time via digital imaging. Using the CCT’s lab, the team has produced ASTM Powder Proficiency Testing results with flow rates, apparent density, particle size distribution, and tap density on titanium-based and nickel-based powder and compared data with other companies/labs. Morphology data was also collected for various regolith simulant powder for the MMPACT program. Lastly, the CCT used morphology data to examine the flowability of Inconel 718 powder for Selective Laser Melting (SLM) and Directed Energy Deposition (DED) printers at MSFC. The CCT’s essential work in studying and enabling AM powder characterization has helped and will continue to help study new and refined powders in the AM industry.

Additive Manufacturing↗
NASA NTRSDate not supplied

Space Environmental Effects on Additively Manufactured (AM) Parts on MISSE-9/10

The Materials on International Space Station Experiment (MISSE) experiments have made a continuous presence on the ISS and allowed for testing of performance and durability of materials exposed to the Low Earth Orbit (LEO) space environment. Additive Manufacturing (AM) has been included on several MISSE flights, and many companies (Made in Space and Stratasys) and NASA centers wanted to test various AM material samples. The goal of studying Space Environmental Effects on AM Parts with MISSE 9/10 was to fly promising metal and polymer AM material samples (dogbones) that could have future manufacturing capabilities in space and conduct post-flight analysis of these materials via mechanical and optical properties. On these flights, MISSE-9 contained three Inconel and 12 polymer samples and MISSE-10 included three Inconel and 16 polymer samples. Before flying to the ISS, all the samples underwent thermal vacuum bakeout (at 60°C for 24 hours and 10-6 torr). After bakeout, control and flight experiments were weighed, and optical properties were taken. Optical properties such as solar absorptance and infrared emittance were taken on the control samples and the flight samples (preflight and postflight). To understand more about the mechanical properties of the AM samples, tensile testing was conducted on the samples to determine the yield and ultimate tensile strength of the dogbone samples against the control. Lastly, the torque on the fasteners securing the dogbone samples were loosened and measured using a torque wrench, and they were compared to their preflight torque specification required. Optical properties and masses were recorded before flight, and the postflight results were recorded and collected in June 2022 to study the effects. With the postflight analysis, NASA engineers can now better characterize how UV radiation and thermal cycling affect the material properties.

Materials on International Space Station Experimen↗
NASA NTRSDate not supplied

PRIME: Powder Removal in Microgravity Environments Experiment

- In Additive Manufacturing (AM) with metal powders, layers of material are deposited and fused to form aerospace 3D printed parts - Remnant powder must be removed from interior cavities and channels to fully clean the part - AM cleaning methods have been a topic of interest

Powder Removal↗
NASA NTRSDate not supplied

Microwave AeroGel Volatile Collector (MAGVC) Aerogel and Microwave Radiation Study

The MAGVC is a volatile extraction system that uses microwave radiation to sublimate and collect water trapped in regolith on the lunar surface It is comprised of: - Microwave source (magnetron) - Aerogel-insulated chamber (depicted as a dome) - Volatile storage system (depicted as 4 tanks) - Autonomous operating system

Aerogel↗
NASA NTRSDate not supplied

Thermal Control Coatings Flown on MISSE and METIS

A variety of coatings for passive thermal control were flown on the Materials on International Space Station Experiment (MISSE) 15th and 16th flights and on the Materials Exposure and Technology Innovation in Space (METIS) 1st flight. The MISSE and METIS flights were both in low Earth orbit but had very different results. Space environmental and molecular contamination effects on optical properties are reviewed. Future experiments, including the Regolith Adherence Characterization (RAC) flight to the Moon, are discussed.

space environment↗
NASA NTRSDate not supplied

NASA MSFC Member Introduction for NIST MAMP Consortium

Having consistent powder characteristics are important for ensuring repeatable manufacture of metal parts. The benefits of testing the powder through contamination teams likes us is that we have the test equipment and capabilities that can spot potential issues with powders without having to print anything at all.

NIST↗
NASA NTRSDate not supplied

PRIME ISS Ground Prototype

In Additive Manufacturing (AM) with metal powders, layers of material are deposited and fused to form metal 3D parts. However, in most cases, remnant powder still must be removed from interior cavities and channels to fully clean the part before use. Ground demonstrations such as ultrasonic cleaning have been proven to work during ground testing at MSFC and Florida State University. However, manufacturing in the low gravity environment of space introduces challenges to this powder removal. Therefore, if this concept could be demonstrated in microgravity, the ability to clean AM parts or contaminated parts can bring new advancements to in-space manufacturing (ISM). The goal of this work was to make significant progress on developing an ISS payload using the ultrasonic technology called Powder Removal in Microgravity Environments (PRIME). This would also create new opportunities for in-space manufacturing (ISM) and the additive manufacturing community to develop new standards and practices for powder removal and the cleaning of contaminated parts in space.

Microgravity↗