Investigation of Temperature and Microstructure on the Hugoniot Elastic Limit in Additively Manufactured SiC-B4C Ceramics.

Additively manufactured (AM) ceramic materials provide an unprecedented level of control over specimen geometry superior to the conventional subtractive counterpart. The byproduct of this method includes defects in material geometry such as a high degree of porosity and larger grain sizes. Currently, there is little work done in exploring the microstructure-property-performance relationships of AM ceramics in the context of high velocity impact. Furthermore, the effect of elevated temperature on the Hugoniot elastic limit (HEL) of AM ceramics remains widely unstudied. Laser driven micro-flyer experiments of hypervelocity impact were performed on AM SiC and SiC-B₄C material from UMass Lowell. The Hugoniot elastic limit was measured at high temperatures. Accompanying this, characterization of microstructural features through X-ray Computed Tomography and Scanning Electron Microscopy was conducted to identify the pore and grain size/morphology. Postmortem fractography was performed to determine relevant fracture modes related to failure in AM material including the plastic deformation mechanisms. These findings offer a foundation for optimizing the design of ceramics for extreme environments including applications subjected to high temperatures and hypervelocity impact as well as an understanding of the microstructure-property-performance relationships in AM ceramics.