Study on the morphology-preserving mixing and performance of tungsten-based delay composites via resonant acoustic mixing technology

The preparation of energetic composites has long been challenged by the need to balance uniform dispersion of high-energy components with preservation of their structural integrity. Conventional mixing methods are particularly problematic for systems with large density contrasts: excessive shear forces promote particle fragmentation, whereas insufficient mixing intensity results in non-uniformity, both of which compromise performance reliability. In this study, tungsten powder (W), barium chromate (BaCrO₄), potassium perchlorate (KClO₄), diatomaceous earth, and fluororubber were combined to formulate tungsten-based delay compositions using three approaches: resonant acoustic mixing, mechanical ball milling, and hand mixing. The mixed samples were characterized by morphology, particle size distribution, mixing uniformity, combustion performance, and thermal properties. Discrete element simulations were further employed to elucidate the underlying mechanisms of resonant acoustic mixing and ball milling. The results demonstrate that resonant acoustic mixing achieves uniform blending while preserving particle morphology, yielding a delay time scatter coefficient as low as 1.20%. By contrast, ball milling caused extensive fragmentation, leading to double-peak DSC profiles characteristic of stepwise reactions and incomplete combustion. Hand mixing preserved particle shapes but yielded poor uniformity and inferior delay accuracy. Overall, this study demonstrates that particle morphological integrity and mixing uniformity play crucial roles in controlling combustion behavior, and highlights the superior performance of resonant acoustic mixing technology in processing high-density-gradient energetic composites.