Wear Resistant Plasma Sprayed Coatings For Radiation Shielding
NASA’s Artemis program aims to return to the moon in search of scientific discoveries and establish a habitat using in-situ resource utilization. However, the past lunar explorations presented challenges, such as thermal cycles, solar and intergalactic cosmic radiation, and severe abrasive interaction of sharp lunar regolith particles. Dust mitigation and radiation shielding have become the most important concerns for lunar structural components and rovers which can fail abruptly without a protective solution. To counter these threats, the Plasma Forming Laboratory (PFL) at Florida International University (FIU), in collaboration with NASA, has developed a novel multifunctional coating to protect the components synergistically against abrasion, erosion, and radiation.
The titanium-boron nitride composite coatings were prepared using an atmospheric plasma spray technique from engineered composite powders. The coatings were developed as a part of NASA’s Metallic Environmental Resistant Coatings Rapid Innovation Initiative (MERCRII) project. The MERCRII team consists of two NASA centers (NASA Marshall Space Flight Center (MSFC), Huntsville, Alabama, and NASA Langley Research Center, Hampton, Virginia); the Plasma Forming Laboratory at FIU as an academic partner; and Plasma Processes, Huntsville, Alabama, as a private partner.
The coatings were subjected to extensive characterization and tribological study with lunar mare simulant JSC-1A, which shows tremendous improvement in the wear performance. The coatings subjected to neutron radiation shielding experiments at NASA Langley Research Center exhibited significantly improved neutron attenuation capacity compared to the substrate. The coatings with excellent radiation shielding results were sent to the International Space Station as a part of MISSE-17 (Materials International Space Station Experiment) in March 2023. The coatings, mounted on a platform with other testing samples are being exposed to solar and intergalactic cosmic radiation. After six months, a crew of astronauts will bring the material back to Earth for analysis. In the meantime, NASA and FIU will test the coatings against the harsh erosive environment and thermal vacuum cycles. The findings from this study will help develop and construct materials and systems that will be used in Human Landing Systems (HLS) in future lunar explorations, including Artemis missions.
