Defining microstructural tolerance limits of defects for SiC armor

Near theoretical density, >99.5%, has generally been used to assess structural integrity and is commonly used as a key acceptance criteria for armor product selection. However, it is unknown whether a slight change in, residual porosity, the shape and dispersity of pores are detrimental to the dynamic performance of the product. This study aims to define the upper limit of acceptable defects (i.e. porosity and inclusions) and to quantify the microstructure of SiC armor. The key goal within this study is to develop an understanding of the factors critical to the design, fabrication and testing of micro/macro-tailored ceramics with enhanced multi-hit ballistic performance. Commercial SiC samples with varied densities (3.0-3.2 g/cm ³) have been obtained and microstructural assessment on polished sections has been performed. Pore size distribution and average pore size have been calculated using image analysis. Nearest neighbor distance distributions of different microstructures have been found. Tessellation analysis has been performed to find out the degree of inhomogeneity in microstructures. Finally, pair correlation functions have been determined.