NiFeCoCr high entropy alloy(HEA) with non-equal atomic ratio was adopted as a new bonding phase of tungsten heavy alloys. 90W-NiFeCoCr alloy was prepared by spark plasma sintering. The effects of sintering temperature on the microstructure and mechanical properties of the alloy were investigated by scanning electron microscopy(SEM), energy microanalyzer spectrum(EDS), X-ray diffractometer(XRD), electron probe microanalyzer(EPMA), transmission electron microscope(TEM) and mechanical experiments. The results show that in the microstructure of the alloy, the HEA binder phase is formed, which is the γ(Ni-Fe-Co-Cr, W) phase with face-centered cubic(FCC) structure, and the Cr2O3 phase with close-packed hexagonal(HCP) structure appears. The relative density of the alloy increases first and then decreases with the increase of temperature. After sintering at 1 250 ℃, the relative density reaches the highest of 98%, the W grain size is fine (≤10 μm), the tensile strength reaches a maximum of 1 409 MPa, and the fracture morphology is mainly W-W dissociation fracture. The solid solution strengthening of HEA, the fine grain strengthening of W and the dispersion strengthening of the segregated phase Cr2O3 are the main reasons for the higher strength. © 2024 Central South University of Technology. All rights reserved.
