Insights into Spallation Mechanisms of Thermal Protection System Materials

An effort investigated how internal pressure builds within thermal protection system (TPS) materials subjected to high-enthalpy environments, aiming to link gas evolution and microstructural interaction to degradation and failure modes like spallation. Complementary experimental approaches provided both chemical and mechanical insight into subsurface processes.

In-depth pressure measurements from the Hypersonic Materials Environmental Test System (HyMETS) quantified dynamic subsurface pressure buildup as gases evolved, while mass spectrometry characterized volatile species released during heating. The analysis separated low-temperature desorption events—such as early water release before large permeability changes—from gases produced by high-temperature pyrolysis of the polymer backbone.

Those data established a quantitative connection between chemical decomposition and mechanical response.

spallation, thermal protection, tps, high enthalpy, hymets, mass spectrometry, pyrolysis, desorption, subsurface pressure, gas evolution