Measurement of ceramic powders using instrumented indentation and correlation with their dynamic response

This article discusses an experimental approach for measuring the properties of individual powder particles sized between 25 μm and 100 μm of four common very hard ceramic materials: tungsten carbide, alumina, boron carbide, and silicon carbide. Fused silica is also investigated as the reference material. Experiments on the individual powder particles were performed to a depth of 100 nm and critically compared against consolidated compacts of the same materials. To draw a correlation between the instrumented indentation measurement and their dynamic properties, this investigation exploits the low modulus to hardness ratio of these materials, whether tested as powder or in consolidated form. The indentation experiments, as they were performed in this study, lie within a regime that allows the use of the expanding cavity model to provide a more rigorous mechanical analysis to the results. Through the use of the expanding cavity model framework, this article concludes by discussing the plausibility of a relationship between the hardness of the individual powder particles, static and dynamic strength, and the high rate deformation behavior of compacts fabricated from these hard ceramic powders.