UQ eSpace

Abstract

The strength of the Fe45Ni25Cr25Mo5 high-entropy alloy was reinforced through precipitation hardening and minor addition of titanium and carbon elements. The aged Fe45Ni25Cr25Mo5 alloy obtained a peak hardness of 307.12 HV at 900 ˚C for 48 hours. This alloy was strengthened through the formation of long thin needle-like ! phase precipitates. 5 at.% of titanium and carbon were added to the alloy respectively to further improve its strength and restrict the growth of the needle-like precipitates during aging treatment. The involvement of the reinforcement content induced the formation of (Ti, Mo, C)-rich carbides, and hence increased the hardness of the alloy to 246.45 HV. Aging treatment was performed in (Fe45Ni25Cr25Mo5)90Ti5C5 alloy to investigate the strength evolution of this alloy. The best aging performance was obtained when the alloy was aged at 800 ˚C for 96 hours with an optimum hardness of 402.24 HV. The minor elemental addition has refined the needle-like precipitates from the size larger than 20 µm to the size smaller than 10 µm. As a result, (Fe45Ni25Cr25Mo5)90Ti5C5 alloy was reinforced by the high volume fraction of fine needle-like precipitates and nanosized precipitates, fine divorced eutectic structures, as well as the (Ti, Mo, C)-rich carbides.