Effect of Sintering Pressure on the Microstructure and Properties of AlCoCrNiFe High‐Entropy Alloys Fabricated via Hot Oscillating Pressing

In this work, AlCoCrNiFe high‐entropy alloys (HEAs) were fabricated via hot oscillating pressing (HOP) under different sintering pressures (50, 55, and 60 MPa), and the effects of sintering pressure on the alloy's microstructure and properties were systematically investigated. Results indicate that HOP‐sintered samples exhibit superior density, microstructural uniformity, and overall performance compared to conventional hot pressing (HP)‐sintered counterparts. With increasing sintering pressure, the original powder particle boundaries of the HEAs melt gradually, the densification rate increases, and the samples’ density, hardness, and corrosion resistance are all enhanced. When the HOP pressure reaches 60 MPa, the HEAs achieve optimal properties: a maximum density of 95.91%, a maximum Vickers hardness of 443 HV ₁ , and superior corrosion performance in 3.5 wt% NaCl solution (minimum corrosion current density of 14.9 μA/cm ² and minimum corrosion rate of 0.104 mm/year). This work provides valuable guidance for the optimization of HOP technology and the development of high‐performance HEAs.