The hidden nature of the dynamic high-pressure strength of diamond-TiC composite

Abstract

The strength of diamond is critical for both static and dynamic high-pressure research. Under the compression of shock waves in the range of hundreds of gigapascals, single-crystal diamond exhibits strong time-dependent inelastic deformation, making it a crucial issue for the development of an accurate material description of diamond capsules used in inertial confinement fusion (ICF). Here, we propose a dual-media material model for achieving a new ICF alternative substance, where the main medium is diamond particles, and the rest is titanium carbide (TiC) filling the spaces around them. A sample consisting of dual-media has been experimentally manufactured, and the shock compression response has been measured. The stable propagation of shock waves in diamond-TiC (D-TiC) composite was explained through density functional theory and molecular dynamics simulations. Our findings show that TiC creates an environment analogous to hydrostatic pressure confinement. This mechanism not only preserves the structural integrity of diamond under high pressure but also promotes stable shock wave propagation. Moreover, this easily synthesized and cost-effective diamond-based composite offers a promising new strategy for optimizing diamond capsule materials in ICF.