Microstructure evolution and mechanical response of Co-free Ni2CrFeAl0.3Tix high-entropy alloys

• Published in: Journal of alloys and compounds Vol. 931; p. 167523
• Main Authors: Liu, X.X., Ma, S.G., Song, W.D., Zhao, D., Wang, Z.H.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 10-01-2023; Elsevier BV
• Subjects: Ductility; Face centered cubic lattice; High entropy alloys; High-entropy alloy; Mechanical analysis; Mechanical properties; Mechanical property; Microstructure; Precipitates; Solid solutions; Stacking fault energy; Strain hardening; Ti addition; Titanium; Ultimate tensile strength; Ti addition; Microstructure; Mechanical property; High-entropy alloy
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.167523

In this study, microstructure and mechanical behavior of Co-free Ni2CrFeAl0.3Tix high-entropy alloys are investigated. X-ray diffraction analysis show that a simple face-centered cubic (FCC) solid-solution structure is present in Ni2CrFeAl0.3Ti0.1 and Ni2CrFeAl0.3Ti0.2 alloys, while B2-type precipitation appears in Ni2CrFeAl0.3Ti0.3 alloy in addition to the FCC matrix. Tensile results reveal that with an increase in Ti content, the yield and tensile strength of the alloys increases while the ductility decreases, and fortunately a good balance between strength and ductility is attained in Ni2CrFeAl0.3Ti0.3 that exhibits an ultimate tensile strength of 1240 MPa combined with over 10 % fracture strain. This feature can be ascribed to the visible strain-hardening response, reduced stacking-fault energy (ranging from 56.5 to 37.4 mJ∙m−2) and very fine B2 precipitates due to Ti addition. This work would provide an insight into the design of low-cost Ti-containing alloys in the future.
•A novel Co-free Ni2CrFeAl0.3Tix alloy system is investigated.•A good balance of strength and ductility is attained in Ni2CrFeAl0.3Ti0.3 alloy.•The addition of Ti yields reduced SFE values ranging from 56.5 to 37.4 mJ∙m−2.•Fine B2 precipitation plus FCC phase constitute a eutectic-type structure.