Effect of sintering temperature on microstructure and mechanical properties of hot-pressed AlCrFeSi alloy

Abstract AlCrFeSi alloys have emerged as promising candidates for structural components requiring high strength, wear resistance, and thermal stability at elevated temperatures. To clarify the influence of processing conditions, elemental powders were synthesized by high-energy ball milling (HEBM) and consolidated via hot-press sintering (HPS) at 700 °C–1000 °C. Systematic characterization using XRD, SEM, hardness testing, and tribological evaluation revealed a strong dependence of densification and phase evolution on the sintering temperature. The optimum condition was found at 950 °C, where the alloys achieved nearly full densification (∼99.3%), refined microstructures with Al 13 Cr 2 and AlCr intermetallic phases, high hardness (∼495 HV), a reduced friction coefficient (0.37), and maximum fracture toughness of 4.1 MPa·m 1/2 . Further heating to 1000 °C caused grain coarsening and slight property degradation. These results highlight that precise control of the sintering temperature enables the fabrication of dense and wear-resistant AlCrFeSi alloys, providing useful guidance for the design of complex concentrated alloys for advanced high-temperature applications.