Microstructure and mechanical properties of precipitation-hardened cast high-entropy superalloys

ABSTRACT

Recent studies indicated that precipitation-hardened high-entropy alloys (HEAs) possess outstanding properties. It is difficult to obtain substantial precipitated particles for HEAs at the as-cast condition. In this paper, cast precipitation-hardened high-entropy superalloys (HESAs) Ni_48−xCo₁₈Cr_10.5Fe_9.3Al_9.7Ti_4.5Mo_x (at.-%, x = 1, 2, 3) were designed and prepared. All HESAs possess a high-entropy matrix and a fine γ′ particles structure. HESAs have higher ultimate tensile strength and elongation at room temperature than conventional Ni-based superalloys and close yield strength. All HESAs possess high compressive strength at elevated temperature. At 850 °C, the strengths of all alloys are higher than 800 MPa. Solid solution strengthening and precipitation strengthening were discussed. Precipitation strengthening has the greatest contribution to yield strength.

KEYWORDS:

• High-entropy superalloy
• microstructure
• mechanical property
• strengthening mechanism

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 50971051].