B4C based laminates

15 Fracture surface of Si3N4/Si3N4-50%wt%TiN composite (a) and (c) SEI image (b) and (d) backscattered image. 

76 Schematic presentation of symmetric three-layered design of B4C/B4C30wt%SiC laminate. 

Thickness of layers (pm) B4C-30wt%SiC B4C Ooomp(MPa) OfenslMPa) Apparent Kic (MPa.m172) 

The manufactured 90 mm x 90 mm x 10 mm three-layered B4C/B4C-30wt%SiC tiles were tested as armor [67], The photographs of the experiment set-up of the ballistic test as well as a residual impression in the clay box that was used as one of the criteria in the ballistic performance of laminates are shown in Fig. 7.17. The ballistic penetration tests were performed to evaluate the ballistic performance of the laminates. Depth of penetration tests were used to evaluate the ballistic performance of the composite laminates. In addition, pure B4C monolithic ceramics were used as a standard for the test. Test panels were made using the three-layered B4C/B4C-SiC laminate and B4C monolithic ceramic material as the hard face. While the B4C monolithic tile had 100% of its theoretical density, the three-layered B4C/B4C-30wt%SiC laminates had about 3-4% of porosity. A commonly used Spectra fiber-reinforced polymer composite was used as backing plates. The targets were mounted on clay and the projectile was shot at the target at a specific velocity. 

77 (a) A ballistic test setup (b) diameter of the residual impression in the clay box used for evaluation of the performance of the B4C based tiles. 

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