Iranian Journal of Materials Science and Engineering

en Synergistic Impact of Mechanical Alloying Duration and Spark Plasma Sintering Temperature on Microstructure and Properties of CoCrFeNiMn High-Entropy Alloys گروه ریخته گری و انجماد Casting Processes and Solidification Phenomena Research Paper Research Paper This study successfully synthesized the CoCrFeNiMn high-entropy alloy (HEA) using a two-step powder metallurgy approach: mechanical alloying (MA) followed by spark plasma sintering (SPS). The research investigated the effects of processing parameters, specifically MA duration and SPS temperature, on the alloy's microstructure, densification, and mechanical properties. X-ray diffraction (XRD) analysis after 25 hours of MA (ball-to-powder ratio of 10:1) confirmed the formation of a single-phase face-centered cubic (FCC) solid solution. Scanning electron microscopy (SEM) images revealed significant powder particle refinement, with average particle sizes decreasing from initial micrometers to sub-micrometer ranges. The alloyed powders were then consolidated via SPS at temperatures of 800°C, 900°C, and 1000°C (40 MPa, 10 min in argon). Detailed analysis of the sintered samples showed relative densities ranging from 95.78% to 96.77%, with the highest density (96.77%) achieved at 1000°C. Vickers microhardness measurements exhibited a peak hardness of 446 HV at 900°C, with a decrease to 420 HV at 1000°C, primarily due to grain growth. This research establishes the combined MA and SPS approach as effective for producing high-density, high-hardness HEAs, underscoring the critical role of processing parameters in tailoring their final properties.   High-entropy alloys (HEAs),Mechanical alloying,Spark plasma sintering (SPS),Microstructural refinement,Vickers hardness 89 98 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-5900-2&slc_lang=en&sid=1 ALireza hajialimohammadi ahajiali@semnan.ac.ir 1800319475328460022063 1800319475328460022063 Yes Faculty of mechanical engineering, Semnan university, Semnan, Iran