Initial stage of titanium oxidation in Ti/CuO thermites: a molecular dynamics study using ReaxFF forcefields
Hicham Jabraoui1, Alain Estève1, Sungwook Hong2
1LAAS-CNRS, University of Toulouse, 31077 Toulouse, France. rossi@laas.fr.
Physical Chemistry Chemical Physics : PCCP
|April 15, 2023
Summary
The Ti/CuO thermite reaction preferentially forms titanium monoxide (TiO) at low temperatures. Oxygen migration fuels the reaction, unlike aluminum/copper oxide systems, revealing enhanced Ti-based thermite reactivity.
Area of Science:
- Materials Science
- Chemical Engineering
- Computational Chemistry
Background:
- Thermite reactions are energetic processes with broad applications.
- Understanding the initiation mechanisms of Ti/CuO thermite is crucial for controlling its reactivity.
Purpose of the Study:
- To elucidate the primary driving mechanisms in the early stages of the Ti/CuO thermite reaction.
- To compare the reaction pathways of Ti/CuO with Al/CuO systems.
Main Methods:
- Reactive forcefields were employed within molecular dynamics simulations.
- Simulations were conducted to analyze atomic behavior and mass transport at various temperatures.
Main Results:
- Titanium monoxide (TiO) forms preferentially over titanium dioxide (TiO2) at low temperatures (200 K).
- Copper(II) oxide (CuO) decomposition begins at 600 K, with oxygen transfer to titanium.
- Above 700 K, oxygen atoms migrate across the titanium oxide layer to react with titanium fuel.
Conclusions:
- The Ti/CuO thermite reaction is characterized by oxygen migration to titanium fuel.
- Ti-based thermites exhibit enhanced reactivity due to lower-temperature CuO decomposition compared to Al/CuO systems.
- This study provides novel insights into thermite initiation mechanisms.
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