This project seeks to investigate the viability of an alternative penetrator-defeating mechanism based on the use of impedance engineering to manage stress wave reflections. Stress waves, especially tensile waves, are problematic for ceramics as ceramics are an order of magnitude weak in tension than in compression. Theoretical calculations and simulations using Spectrum
were used to validate the hypothesis.
Fabrication of such impedance engineered laminates were shown to be achievable via
traditional hot-pressing and robocasting. Fully dense (>99% TD) SiC with solid-state sintering
additives were produced using robocasting with a flexural strength of 469 MPa (3PBT) and Young’s Modulus of approximately 430 MPa (ultrasonic techniques). Robocasting of SiC-B4C composites across the entire range of compositions was shown to be possible and pressureless sintered to high densities (>97% TD). Robocasting of ceramics and ceramic matrix composites based on SiC-B4C forms the bulk of the experimental work and is critical in ensuring that they can be deployed in armour applications. Characterisation of the fabricated ceramics showed mechanical properties comparable to other SiC/B4C materials in literature. While success in the ultrasonic characterisation of the interfaces was limited, a deeper understanding of the proposed mechanism was achieved.