Using Hardness Tests to Quantify Bulk Plasticity and Predict Transition Velocities in SiC Materials

It has long been known that a relation exists between a material's hardness and its gross impact performance; however, the nature of this relationship has not been understood to a degree useful in materials development. Many studies have shown that harder ceramics tend to display better ballistic performance. In addition, some research has suggested that a material's potential for inelastic deformation (or its “quasi‐plasticity” – a bulk property) may also play an important role in its resistance to penetration. Methods of quantifying the bulk plasticity of a ceramic material are, however, extremely limited. The current study continues an investigation into a recently proposed technique to (1) quantify bulk quasi‐plasticity in SiC materials, and (2) use the “plasticity” value along with a hardness value to predict the transition velocity of potential armor ceramics. The transition velocity values predicted by this approach generally show excellent agreement (within 5% in most cases) with experimentally determined velocities. In addition, the robustness of this predictive technique is demonstrated through the use of multiple operators and multiple hardness testing units.