Insights into aging mechanism of Ti-metal based pyrotechnics and changes in thermo-kinetic characteristics

Abstract Metal fuels with high energy density have been receiving attention recently as alternatives to fossil fuels in propulsion systems, power generation applications, and energy storage technology. However, to adopt metal fuels for such purposes, maintaining the designed performance level and greater reliability are required. Thus, aging analysis as well as thermal analysis of metal fuels must be conducted thoroughly prior to such practical applications. In order to identify an aging mechanism, the present paper investigates the variation in both thermodynamic characteristics and reaction kinetics of titanium hydride potassium perchlorate (THPP) under aging. Some chemical and physical defects of aged samples were also found by x-ray photoelectron spectrometer (XPS) and field emission scanning electron microscope (FE-SEM). The influence of aging on combustion reactions of THPP was elucidated by carrying out the non-isothermal differential scanning calorimetry (DSC) and thermogravimetry (TGA). Based on the changes in thermodynamic characteristics and reaction kinetics, the altered reaction mechanism due to aging was investigated. Certain samples aged under humid environments had different activation energy pathways for reaction progress due to an increased amount of TiO2, which can give rise to severe changes in lifetime and stability after all.