TEM Studies of Protective Al Coatings on Kapton H

Abstract

Polymeric materials undergo rapid erosion when exposed to the harsh low-earth-orbit (LEO) environment. Coatings can reduce the erosion rate of polyimide Kapton from atomic oxygen (AO) attack. Specifically, we are investigating how thin Al coatings can protect Kapton. Protective Al layers with variations in layer thickness and growth conditions were deposited on Kapton H. The quality of these protective coatings were evaluated by mass loss measurement and compared to Kapton alone and the SiO2 coating, where dramatically decreased erosion rate was noted. To understand how these coatings protect Kapton as well as how the AO interacts with the coatings, we are investigating the microstructure of these coated materials by plane view and cross-sectional transmission electron microscopy (TEM) methods. To understand the AO degradation mechanism, we attempted to correlate the mass loss with growth conditions and microstructures. We noted a slight improvement in erosion resistance of the Al coating due to the presence of the dendrimer, but a major improvement when the Al coating is deposited under ultrahigh vacuum conditions.

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Acknowledgments

The authors would like to thank Mr. Michael McCarthy at International Instrument Sales, Dr. Gregory M Becker at RMC, Mr. Helmut Gnaegi at Diatome Ltd, Biel, Switzerland and Mr. Joseph Suhan at Carnegie-Mellon University for the help with cross-sections using ultramicrotome. One of the authors (J Yang) was supported through NASA Faculty Fellowship. The research has been supported by MURI-AFOSR (#F49620-01-1-0336).

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Correspondence to Judith C. Yang.

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Yang, J.C., Xu, H., Li, L. et al. TEM Studies of Protective Al Coatings on Kapton H. MRS Online Proceedings Library 851, 535–540 (2004). https://doi.org/10.1557/PROC-851-NN9.8

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