Low-Energy Mechanical Activation Impact on the Ignition Temperature of 3Ni + Al Powder Mixture

Abstract The effect of low-energy mechanical activation (LEMA) of 3Ni + Al powder mixtures on their ignition temperature was theoretically and experimentally investigated. LEMA proved instrumental in creating structural defects and significant morphological changes, thereby critically influencing subsequent high-temperature synthesis kinetics. It was determined that LEMA reduces ignition temperature by lowering chemical reaction activation energy and increasing the interfacial surface area. During the initial stages of activation, crystal defect formation served as the primary mechanism, raising the internal energy and lowering the ignition barrier. Extended activation led to prominent morphological transformations, including particle size reduction, decreased structural heterogeneity, and layered mechanocomposite formation. These alterations transitioned the reaction mechanism from diffusion-controlled to interfacial-controlled, subsequently lowering the required activation energy. The findings underscore the critical role of morphological evolution in enhancing system reactivity, especially under prolonged activation. This research establishes a scientific foundation for developing efficient methods to produce Ni–Al-based materials, highly relevant for high-temperature applications in the energy, aerospace, and chemical industries.