High-Energy Mechanical Alloying for Refractory High-Entropy Alloy Powder Development

The fabrication route to meet the desired powder properties is as important as determining the appropriate powder materials for certain applications. Among the several powder preparation and development techniques, the advantageous solid-state processing of high-energy mechanical alloying produces metal powders with minimal component segregation and ultrafine microstructures. Moreover, this technique’s capability to process materials with high and varying melting temperatures makes it a great candidate to develop refractory high-entropy alloys (RHEAs). This study utilized mechanical alloying to manufacture two RHEA powders, MoNbZrTiV and AlNbTaTiV. The powder features such as particle size, morphology, elemental distribution, and flowability were comprehensively investigated. Particle hardness was systematically determined to assess the powders’ compatibility with potential substrates when coated using cold spray additive manufacturing. Purposely, using mechanical alloying to produce a wide range of emerging materials such as RHEAs provides versatility in developing powder feedstocks for various thermal spray and cold spray processes.