IDR/Collaborative Research: Activities in Thermal Spray Processing and Volcanology

William Marsh Rice University, Houston TX

Investigators

Abstract

The research objective of this Interdisciplinary Research (IDR) collaborative award is to explore interdisciplinary parallels between volcanology and thermal spray materials processing, notably the behavior of molten materials at extreme temperatures and pressures. Volcanic magma is subjected to high (700-1200°C) temperatures and pressures approaching 1000 atmospheres. Thermal spray involves impinging molten (1000-2000°C) metallic or ceramic micro-particles at 100-200 m/s onto substrates, where instantaneous pressures can reach 10000 atmospheres underneath the impacting "splat". The collaborative link stems from a recent discovery of highly nanoporous structures on the underside of frozen splats, the hypothesized mechanism of which is bubble nucleation due to rapid depressurization; this is known to occur in magma during volcanic eruption. Accordingly, existing geologic models and controlled thermal spray processing will be used to better understand this phenomenon for a wide range of materials and environmental variables. The approach taken will be to (1) utilize volcanologic modeling techniques and experimental parameter space to explore the capability of thermal spray to produce "geo-inspired" nanoporous thin films and coatings on a useful scale and (2) use thermal spray processing, specifically splat formation, to develop microscale experiments in which the high-temperature properties of volcanic materials may be measured systematically. If successful, the benefits of this research will include robust design tools to fabricate useful nanoporous surfaces and structures of a wide range of materials using thermal spray, a multi-billion dollar industry with significant infrastructure. This would also introduce a new technological "pull" for thermal spray driving further fundamental studies and innovation. In addition, it would create a reliable tool to address highly debated topics in magma behavior, important for understanding and prediction of eruptions. For outreach, the program will take advantage of the highly visible and dynamic nature of both fields, to facilitate dissemination of complex scientific concepts to undergraduates, under-represented pre-collegiate students, and senior citizens.