Atomic Oxygen effects evaluation on high thickness Carbon-Carbon nano-coated structures for re-entry applications

Paper number

IAC-18,C2,8,1,x47091

Author

Dr. Andrea Delfini, Italy, Sapienza University of Rome

Coauthor

Dr. Antonio Vricella, Italy, Sapienza University of Rome

Coauthor

Dr. Roberto Pastore, Italy, Sapienza University of Rome

Coauthor

Prof. Fabio Santoni, Italy, Sapienza University of Rome

Coauthor

Prof. Mario Marchetti, Italy, Sapienza University of Rome

Coauthor

Prof. Franco Gugliermetti, Italy, Sapienza University of Rome

Coauthor

Dr. Marta Albano, Italy, Agenzia Spaziale Italiana (ASI)

Coauthor

Prof. Giuseppe Familiari, Italy, Sapienza University of Rome

Coauthor

Dr. Ezio Battaglione, Italy, Sapienza University of Rome

Coauthor

Dr. Roberto Matassa, Italy, Sapienza University of Rome

Year

2018

Abstract

Since the beginning of the Space Age, the Re-entry environment has been crucial both for manned and unmanned missions. Thus, along high temperatures and plasma, created during the re-entry phase, several issues must be considered in order to use new technologies and materials.  Carbon-Carbon composites are
widely used for high temperatures applications, included Thermal Protection Systems for Re-entry, and the effect of Space Environment have to be considered in order to design and produce a re-entry structure that can be used also for long duration missions.  In this work high thickness Carbon Carbon has been
tested  in  the  Atomic  Oxygen  Facility  at  the  Aerospace  Systems  Laboratory  of  Sapienza  University  of Rome,  evaluating  the  erosion  and  oxide  creation  on  the  TPS  surface  due  to  Atox  interaction.   This interaction can affect the material and degrade the thermal,  physical and mechanical properties of the TPS  structure,  thus  an  evaluation  of  these  effect  is  mandatory.   The  experimental  campaign  has  been carried  out  setting  the  Atomic  Oxygen  generator  at  a  fluence  of  1.5E21  atoms/cm2,  for  a  time  of exposure of 1000 equivalent sun hours.  The material involved in the campaign is a high thickness Carbon Carbon,  made  with  a  customized  CVI  process.   Two  categories  of  sample  have  been  considered:  first of all, naked CC samples, secondly CC samples coated with an Aluminum Oxide varnish charged with 0.5% of SiO2 nano-spheres. To evaluate the mechanical erosions rate and the amount of oxygen grown on the surface of the photo-electroactive materials, scanning electron microscopy (SEM) technique coupled with dual energy dispersive spectroscopy  (dEDS)  detectors  has  been  performed  for  surface  morphological  observations  correlated to the surface chemical identification.  Furthermore,  the EDS analyses will establish quantitatively the amount of oxygen distributed on the observed surface through bi-dimensional chemical mapping in order to understand the degradation mechanisms for improving the efficient energy conversion devices.

Abstract document

IAC-18,C2,8,1,x47091.brief.pdf

Manuscript document

IAC-18,C2,8,1,x47091.pdf (🔒 authorized access only).

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