Detonation Synthesis of Nanomaterials
Abstract
This project will study fundamental aspects of detonation synthesis of ceramic materials. The research will be guided by the hypothesis that the extreme pressures, temperatures, and chemically-reactive environments produced for short times by detonation can be harnessed to synthesize ceramic nanomaterial that are difficult or impossible to produce by most common synthesis methods. The three technical objectives for the project are: 1) design and construct a research detonation chamber; 2) investigate synthesis of ceramic materials using the extreme pressures, temperatures, and chemically reactive environments; and 3) design new synthesis methods by combining computational tools that predict pressures and temperatures inside blast waves with thermodynamic simulations that predict equilibrium phases at known conditions. A new detonation chamber will be designed, built, and tested to enable fundamental studies in the other technical tasks. Although an existing chamber is available for materials synthesis, several improvements are needed. The purpose-built chamber will provide a more controlled environment for detonation synthesis, which will reduce time required to prepare for a test and minimize sources of impurities. In addition, the chamber will enable collection of data on pressures and temperatures that are needed to elucidate the mechanisms of synthesis during detonation. The chamber will also accommodate in-situ, real-time characterization of the chemical environment during detonation. Fundamental studies of detonation synthesis will be built around three model systems designed to test different hypotheses and provide insight into detonation synthesis mechanisms. Formation of SiC will systematically examine the effects of process parameters such a explosive composition and the addition of inert diluents on detonation characteristics such as detonation velocity, the von Neumann spike pressure, Chapman-Jouguet point, and time duration of the reaction zone. Statistical methods will be used to separate the effects of process parameters on the detonation environment, which will allow for new insight into the role of pressure, temperature, and reaction zone duration on SiC formation, new knowledge of the effect of carbon activity on the stoichiometry of ZrCx ceramics, and elucidation of phase transformation kinetics for stishovite formation. A science-based methodology will be established to make detonation synthesis a general approach for synthesis of nanosized ceramic particles. Thermochemical simulations will be used to identify regimes of pressure, temperature, and chemical activity for stability desired phases. That information will be combined with predictions of detonation pressure, temperature, and chemistry from an available hydrocode to design explosive charge compositions and identify precursors that will the requisite conditions for synthesis of desired nanosized ceramic particles. The overall outcome will be a new paradigm for materials discovery and synthesis that utilizes the extreme pressures, temperatures, and chemical reactivities present during detonation.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 14, 2019
- Source ID
- W911NF1810155
Entities
People
- William G. Fahrenholtz
Organizations
- Army Contracting Command
- Missouri University of Science and Technology
- United States Army