Exploration of the toughness of binary-ternary ceramics

The desire to make tough and damage tolerant ceramics has long been a challenge in structural materials. Although significant progress has been made in developing ceramic matrix composites (CMCs) as the most common solution, challenges associated with manufacturing net-shaped components have restricted their broader application. Non-equilibrium synthesis of elemental powders provides new opportunities for near net shape processing of tough monolithic ceramics that comprise binary carbides and ternary MAX phases. This study presents a detailed numerical study of the stiffness-toughness trade-off in such a binary-ternary system. Specifically, we investigate the influence of the ternary phase clusters’ volume fraction, shape, and shear strength. The key finding of this study is that decreasing the strength of the ternary phase precipitates can increase the toughness without significant loss of stiffness. Increasing the aspect ratio of the ternary precipitates also increases toughness, but at the cost of reduced stiffness. Increasing the ternary volume fraction will also increase toughness, albeit at the cost of reduced stiffness. Our results are expected to serve as a design tool to help vector the processing of binary-ternary ceramics for specific applications.