Effect of Silicon and Mechanical Alloying on Microstructure and Grain Evolution in CuAl and CuAlSi Alloys

Abstract. This research examines the influence of Si addition in CuAl alloy, and the effect of mechanical alloying on the microstructure and elemental distribution of CuAl and CuAlSi alloys, fabricated using powder metallurgy. SEM, micro-XRF, and EDX analyses were conducted to study morphological changes, compositional uniformity, and microstructural evolution. Mechanical alloying was found to introduce strain and defects, which, coupled with sintering, facilitated grain boundary movement and coarsening. Micro-XRF and EDX results showed improved elemental distribution in ball-milled and sintered samples compared to as-is alloys. In CuAlSi alloys, the equimolar composition supported uniform element distribution, though oxidation during sintering reduced the metallic Cu content. Sintering, especially following mechanical alloying, improved the microstructure by increasing grain compactness and refining elemental distribution. These modifications enhance the alloys' mechanical properties, making them suitable for high-performance applications.