Enhanced strength in Co-free Ni47.5-xFe25Cr25AlxTi2.5 high entropy alloys via introducing dual precipitates

Synergistic strengthening mechanisms (e.g. solid solution strengthening, grain/twin boundary strengthening, dislocation strengthening, and precipitation strengthening) have been shown to effectively achieve a balance between strength and ductility of mechanical properties of metal materials. In this...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of materials research and technology 2023-07, Vol.25, p.5663-5673
Hauptverfasser: Xu, Xiaotao, Zhao, Yuhong, Li, Huanqing, Zhang, Xiaobo, Pan, Yue, Wang, Shuai, Hou, Hua
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Synergistic strengthening mechanisms (e.g. solid solution strengthening, grain/twin boundary strengthening, dislocation strengthening, and precipitation strengthening) have been shown to effectively achieve a balance between strength and ductility of mechanical properties of metal materials. In this study, Co-free AlxNi47.5-xFe25Cr25Ti2.5 high entropy alloys (HEAs) mainly strengthened by grain boundary/twin-precipitation were successfully prepared by combining rolling and annealing. The phase-field method was used to demonstrate that twins enhance the Hall-Petch effect by introducing additional twin boundaries. Only a small amount of lamellar L12 phase is precipitated in the aged Al2.5 HEA. The tensile strength is 1086 MPa and the elongation is 30.8%. With the increase of Al content, the volume fraction of L12 phase in the alloy increases, and the bulk B2 phase is precipitated. When the Al content increases to 7.5 at. %, the strength of the alloy increases to 1757 MPa, but the plasticity is catastrophically reduced to only 3.4%. The excellent strength of aged Al7.5 HEA is mainly due to the good combination of grain/twin boundary strengthening and precipitation strengthening.
ISSN:2238-7854
DOI:10.1016/j.jmrt.2023.06.266