SYNTHESIS OF METASTABLE PHASES IN AI-Nb POWDERS BY MECHANICAL ALLOYING

This paper explores the synthesis of metastable phases in aluminum-niobium (Al-Nb) powders through mechanical alloying, aimed at addressing challenges in producing niobium trialuminide (NbAl3) as a structural material. The objective is to achieve a homogeneous synthesis of NbAl3 and amorphous phases, which can provide solutions to issues like brittleness and limited homogeneity range associated with traditional methods. The study employs mechanical alloying, a solid-state powder processing technique involving repeated welding, fracture, and rewelding of powder particles at room temperature. This method significantly reduces diffusion distances and enhances the alloying process due to increased diffusivity arising from crystalline defects. The results indicate successful formation of supersaturated solid solutions, stable and metastable crystalline intermediate phases, as well as amorphous phases. The findings contribute to the field of materials science by outlining an effective approach to synthesizing phases with desirable properties for high-temperature applications, demonstrating the potential of mechanical alloying in the advancement of advanced metallic materials.