The Effect of Mechanical Activation of Elemental Powders on Combustion Synthesis of NbAl₃

Abstract:

The effect of mechanical activation procedures on the combustion synthesis of NbAl3 was investigated. The activation was carried out by a two-step high energy ball milling procedure. In the first milling, aluminum and niobium were milled separately (pre-activation). The mixture of pre-activated powders was then activated in the second milling. Reaction synthesis, by simultaneous combustion mode, was conducted on compacted pellets made of powder mixtures with and without pre-activation. The thermal behavior of the compacted pellets upon heating was recorded and the main thermal combustion reaction characteristics were evaluated. The two-step procedure produced aggregates with a globular dispersion of niobium due to increased particle hardness and decreasing mean particle size during pre-activation milling. Analysis of pellet thermal behavior showed the two-step milling procedure could enhance reaction performance by increasing maximum reaction heating rate and temperature gain during reaction.

• Periodical: Materials Science Forum (Volumes 660-661)
• Pages: 335-340
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.660-661.335
• Online since: October 2010
• Authors: Cláudio José da Rocha, Ricardo Mendes Leal Neto
• Keywords: Combustion Synthesis (CS), High-Energy Ball Milling (HEM), Nb-Al

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