Microstructure evolution of WMoNbTiCrAlx (x = 0, 0.25, 0.5, 0.75, 1) multi-principal element alloys Articles uri icon

publication date

  • September 2025

start page

  • 107225-1

end page

  • 107225-11

issue

  • 107225

volume

  • 131

International Standard Serial Number (ISSN)

  • 0263-4368

Electronic International Standard Serial Number (EISSN)

  • 2213-3917

abstract

  • Multi-principal element alloys (MPEAs) based on refractory metals have been studied as potential candidates to
    replace Ni-based superalloys due to their superior melting temperatures and the promising initial high-
    temperature properties demonstrated by certain compositions. However, a significant drawback of these re-
    fractory metal-based alloys is their high density and low ductility at room temperature. It is known that the
    addition of Al in MPEAs contributes to reducing density, increasing hardness, and stabilizing the BCC phase. In
    this study, the influence of Al on the microstructure of five new multi-principal element refractory alloys pro-
    duced by arc melting, using high-purity raw elements, WMoNbTiCrAl¿ (x = 0, 0.25, 0.5, 0.75, and 1), was
    analyzed. ThermoCalc software was utilized to support the interpretation of the experimental results. Scanning
    electron microscopy (SEM) and X-ray diffraction (XRD) were performed on all alloys in both as-cast and heat-
    treated (1200 ¿C/24 h) conditions. Additionally, electron backscatter diffraction (EBSD) analyses were per-
    formed on the heat-treated alloys. The as-cast alloys exhibited a highly segregated BCC phase with a dendritic
    structure. After heat treatment, the alloys predominantly presented a BCC phase, with a small volume fraction of
    the Laves phase being observed. Nanoindentation tests indicated that the addition of Al increases hardness, from
    10.5 to 12.2 GPa. Regarding density, there was a decrease with increasing Al content, from 9.7982 to 8.7745 g/
    cm3.

subjects

  • Physics

keywords

  • multi-principal element alloys; bcc phase; laves phase; hardness; ai addition