In-Situ Techniques to Understand Changes in Surface Chemistry During Ablation
Start Date
2-3-2011 11:30 AM
Description
Ablation is an effective and reliable method largely used in aerospace structures to protect the payload from damaging effects of external high temperatures. Substantial research is required to develop basic knowledge that is required to characterize the response of a high temperature thermal protection system to extreme hypersonic environment. This presentation will provide an overview of experimental techniques that are currently being used to understand the degradation behavior of composite materials used for thermal protection. Advantages and disadvantages of each method will be discussed. In addition, novel in situ quantitative methods of material degradation during high temperature ablation events will be identified. Specific techniques developed by the authors for hypersonic applications will be discussed. For example, in situ Raman spectroscopy during high temperature wear testing of chameleon coatings was employed by the lead author to correlate surface chemistry to measured changes in friction coefficients simultaneously. Chameleon coatings are adaptive coatings that reduce friction coefficient from 25 to 1000 °C for moving assemblies for next-generation hypersonic aircraft and missiles.
In-Situ Techniques to Understand Changes in Surface Chemistry During Ablation
Ablation is an effective and reliable method largely used in aerospace structures to protect the payload from damaging effects of external high temperatures. Substantial research is required to develop basic knowledge that is required to characterize the response of a high temperature thermal protection system to extreme hypersonic environment. This presentation will provide an overview of experimental techniques that are currently being used to understand the degradation behavior of composite materials used for thermal protection. Advantages and disadvantages of each method will be discussed. In addition, novel in situ quantitative methods of material degradation during high temperature ablation events will be identified. Specific techniques developed by the authors for hypersonic applications will be discussed. For example, in situ Raman spectroscopy during high temperature wear testing of chameleon coatings was employed by the lead author to correlate surface chemistry to measured changes in friction coefficients simultaneously. Chameleon coatings are adaptive coatings that reduce friction coefficient from 25 to 1000 °C for moving assemblies for next-generation hypersonic aircraft and missiles.