Comparison of the High Strain Rate Response of Boron/Silicon Carbide and MAX Phase Ceramics Using the Image-Based Inertial Impact Test

Abstract

AbstractThe high strain rate material behaviour of armour ceramics is important for the design of armour systems. The current standard test technique for obtaining high strain rate material properties is the split Hopkinson pressure bar (SHPB). This technique relies on several assumptions including that the sample must be in a state of quasi-static equilibrium and that the sample undergoes uniform 1D deformation. These assumptions limit the ability of the SHPB technique to accurately identify the high strain rate response of ceramics because they fail at extremely low strains, especially when under tensile loading.Recently, the Image-Based Inertial Impact (IBII) test has emerged as an alternative technique that does not rely on the assumption of quasi-static equilibrium and is specifically designed to obtain the high strain rate tensile strength of brittle materials. Therefore, this work focuses on the application of the IBII test to obtain the high strain rate properties of several armour materials including: boron carbide, silicon carbide and the recently developed MAX phase ceramics. Results for the boron and silicon carbide show that there is no rate sensitivity on the identified elastic properties (modulus and Poisson’s ratio) at strain rates on the order of 1000/s. Additionally, results for the tensile strength of boron and silicon carbide compare well with quasi-static values despite exhibiting high scatter. The MAX phase ceramics will be tested in the future and the results will be presented at the conference.Key wordsArmour ceramicsMAX phasesHigh strain rate testingImage-based inertial impact test