21. Sphere Impact Induced Damage in Ceramics: II. Armor-Grade B4C and WC

  1. Jeffrey J. Swab
  1. J. C. LaSalvia,
  2. M. J. Normandia,
  3. H. T. Miller and
  4. D. E. MacKenzie

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291276.ch21

Advances in Ceramic Armor: A Collection of Papers Presented at the 29th International Conference on Advanced Ceramics and Composites, January 23-28, 2005, Cocoa Beach, Florida, Ceramic Engineering and Science Proceedings, Volume 26, Number 7

Advances in Ceramic Armor: A Collection of Papers Presented at the 29th International Conference on Advanced Ceramics and Composites, January 23-28, 2005, Cocoa Beach, Florida, Ceramic Engineering and Science Proceedings, Volume 26, Number 7

How to Cite

LaSalvia, J. C., Normandia, M. J., Miller, H. T. and MacKenzie, D. E. (2005) Sphere Impact Induced Damage in Ceramics: II. Armor-Grade B4C and WC, in Advances in Ceramic Armor: A Collection of Papers Presented at the 29th International Conference on Advanced Ceramics and Composites, January 23-28, 2005, Cocoa Beach, Florida, Ceramic Engineering and Science Proceedings, Volume 26, Number 7 (ed J. J. Swab), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291276.ch21

Author Information

  1. U.S. Army Research Laboratory—Aberdeen Proving Ground AMSRD-ARL-WM-MD Aberdeen, MD 21005–5069

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2005

ISBN Information

Print ISBN: 9781574982374

Online ISBN: 9780470291276

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Keywords:

  • annor-grade ceramics;
  • metallography;
  • shear localization;
  • sub-surface damage;
  • silicon carbide

Summary

Armor-grade B4C and WC cylinders (25.4 mm × 25.4 mm) were impacted with WC-6Co (6 wt.% Co) spheres (6.35 mm diameter) at velocities between 100 m/s and 400 m/s. The recovered cylinders were subsequently sectioned and metallographically-prepared to reveal the dominant sub-surface damage types and change in damage severity as a function of impact velocity. In general, both ceramics exhibited radial, ring, Hertzian cone, and lateral cracks which increased in number and length as the impact velocity increased. The cracking was predominately transgranular for B4C and intergranular for WC. However, unlike SiC and TiB2 (reported in the part I[1]), no evidence of a comminuted region directly beneath the impact center was observed in either ceramic. B4C exhibited severe spallation of material surrounding the impact center. In addition, evidence of shear localization beneath the impact center was also observed. This observation may in part explain the sharp drop in shear strength that B4C exhibits in plate impact experiments when shocked above 20 GPa. In contrast, WC was almost unremarkable in its response to being impact with the WC spheres in that it exhibited a nice spherical crater that is more typical of the response of a metal. The effect of impact velocity on the observed damage and differences in damage between these two armor-grade ceramics will be presented.