Effect of Al Content on Phase Compositions of FeNiCoCrMo0.5Alx High Entropy Alloy

Metals

Svetlana Shalnova¹  Anton Semikolenov²  Oleg Tolochko²  Victor Klinkov²  Maria Salynova²  Tatiana Larionova²  Valentina Andreeva² 

[1] Institute of Laser and Welding Technologies, State Marine Technical University, Lotsmanskaya Ulitsa, 10, 190121 St. Petersburg, Russia;Institute of Mechanical Engineering, Materials and Transport, Peter the Great St. Petersburg Polytechnic University (SPbPU), Polytechnicheskaya 29, 195251 St. Petersburg, Russia;

关键词: high entropy alloys;    σ-phase;    XRD;    phase composition;    microstructure;    hardness;   

DOI  :  10.3390/met11111734

来源: DOAJ

【 摘 要 】

The FeCoNiCrMo_0.5Al_x system with x up to 2.13 was analyzed from the point of view of evolution of the phase composition and microstructure. Cast samples were synthesized by induction melting and analyzed by X-ray diffraction, energy dispersive spectroscopy, scanning electron microscopy, and Vickers microhardness test methods. Phase compositions of these alloys in dependance on Al concentration consist of FCC solid solution, σ-phase, NiAl-based B2 phase, and BCC solid solution enriched with Mo and Cr. Phase formation principles were studied. Al dissolves in a FeCoNiCrMo_0.5 FCC solid solution up to 8 at.%.; at higher concentrations, Al attracts Ni, removing it from FCC solid solution and forming the B2 phase. Despite Al not participating in σ-phase formation, an increase in Al concentration to about 20 at.% leads to a growth in the σ-phase fraction. The increase in the σ-phase was caused by an increase in the amount of B2 because the solubility of σ-forming Mo and Cr in B2 was less than that in the FCC solution. A further increase in Al concentration led to an excess of Mo and Cr in the solution, which formed a disordered BCC solid solution. The hardness of the alloys attained the maximum of 630 HV at 22 and 32 at.% Al.

【 授权许可】

Unknown