Chapter 21. Pre-Impact Damage Assessment of Dra Metal Matrix Composite Encapsulated Sic Ceramics

  1. Hua-Tay Lin and
  2. Mrityunjay Singh
  1. J.M. Wells,
  2. W.H. Green and
  3. N.L. Rupert

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294741.ch21

26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 23, Issue 3

26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 23, Issue 3

How to Cite

Wells, J.M., Green, W.H. and Rupert, N.L. (2008) Pre-Impact Damage Assessment of Dra Metal Matrix Composite Encapsulated Sic Ceramics, in 26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 23, Issue 3 (eds H.-T. Lin and M. Singh), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294741.ch21

Author Information

  1. Army Research Laboratory Weapons Materials Research Directorate APG, MD 21005–5069

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2002

ISBN Information

Print ISBN: 9780470375785

Online ISBN: 9780470294741

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Keywords:

  • evaluation;
  • monolithic;
  • SiC;
  • characterize;
  • infiltration

Summary

Encapsulation of monolithic ceramic materials is one concept for confinement of candidate armor ceramic materials which enables both constraint during ballistic impact and retention of damage fragments for post-impact evaluation by either destructive or non-destructive methods. Non-destructive examination is essential for the pre-impact baseline characterization of consolidated samples, which subsequently will be tested bailistically and then further characterized for damage in the post-impacted condition. Such non-destructive characterization of experimental samples of SiC ceramic tile material encapsulated within discontinuously reinforced aluminum metal matrix composite, DRA, was conducted using x-ray computed tomography, CT. Each sample consisted of one 10 cm × 10 cm × 1.2 cm thick SiC ceramic tile encapsulated with 356/ SiCp/60v%DRA forming a test sample of 15.2 cm × 15.2 cm × 5.3 cm thick overall dimensions. Both digital x-ray radiography and computed tomography were performed on the samples using a custom built ACTIS 600/420 x-ray computed tomography scanner front Bio-Imaging Research, Inc., to characterize and document the “as fabricated” samples prior to planned ballistic testing.

Results of three samples fabricated by the pressure infiltration casting process indicated pre-existing voids in the MMC encapsulant material and substantial multiple cracks in both the MMC and the SiC materials. Such defects in the as-fabricated samples, had they gone undetected, would have been difficult to separate from later anticipated ballistically-induced damage. Also, significant displacement of the SiC tile was detected indicating an undesired repositioning of the SiC tile during the encapsulation casting step. A subsequent sample fabricated by a presssureless metal infiltration process revealed significantly less extensive cracking than observed in the previous samples. This paper discusses the application of x-ray computed tomography (XCT) to pre-impact characterization of encapsulated ceramic target materials.