Microstructure and oxidation resistance of porous NbAl₃ intermetallic prepared by thermal explosion reaction

ABSTRACT

Porous Nb–Al intermetallic was prepared by thermal explosion (TE) of combustion synthesis (CS). The temperature profile, phase composition, open porosity and oxidation resistance of Nb–Al compact were investigated. The results showed that the significant exothermic reaction occurred, which means that an obvious TE appeared during heating. The volume expansion of 190% was observed, and the prepared sample exhibited interconnected pores with an open porosity of 65.7%. The porous NbAl₃ intermetallic showed ‘pest’ oxidation in the temperature range of 500–600°C, and followed the parabolic oxidation law at 400°C. Moreover, due to the highly porous structure, this material had great potential for application to separation and heat insulation at a temperature range of room temperature to 400°C.

KEYWORDS:

• Intermetallics
• niobium–aluminium
• combustion synthesis
• thermal explosion
• porous material
• microstructure
• oxidation
• parabolic kinetics

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (51574241 and 51874305).