Development of Oriented β -Si 3 N 4 for Ballistic Protection Final Presentation. Lance Blakeman Advisor: Professor Trice. Ballistic Protection. Break projectile using a very hard surface Prevent projectile or fragments from penetrating Absorb the residual energy using soft backing.
Advisor: Professor Trice
Many ceramics are suitable for portable armor.
They have high: hardness, fracture toughness, flexural strength.
Marc André Meyers, Dynamic Behavior of Materials, John Wiley & Sons, Inc., New York, New York, 1994.
All data from Ceradyne.com
Equiaxed – dimensions ≈ in all directions
99% of grains in typical powder sample following formation
Hexagonal rods. Can grow, be elongated further
1% of grains in a typical sample of powderMicrostructure of Si3N4
Image Source: R.W. Trice and J.W. Halloran, “Mode I Fracture Toughness of a Small-Grained Silicon Nitride: Orientation, Temperature, and Crack Length Effects,” J. Am. Ceram. Soc., 82  2633-40 (1999).
Micrograph Source: Rodney W. Trice and John W. Halloran, “Mode 1 Fracture of a Small-Grained Silicon Nitride,” J. Am. Ceram. Soc., 82  2633-40 (1999).
1Desiderio Kovar, Bruce King, Rodney Trice, and John Halloran, “Fibrous Monolithic Ceramics,” J. Am. Ceram. Soc., 80  2471-87 (1997).
Source: Rodney W. Trice, Ph.D. thesis. University of Michigan, 1998.