Microstructure and Mechanical Properties of a New Refractory HfNbSi_0.5TiVZr High Entropy Alloy

Abstract:

A new refractory alloy HfNbSi_0.5TiVZr was synthesized by induction levitation melting with the aim to achieve an excellent strength and toughness balance of the Hf-Nb-Ti-Zr based alloy. The as-cast alloy with density of ρ=7.75g/cm³ and microhardness of H_v=464 had the microstructure consisting of bcc solid solution with little vanadium rich phase and fine intermetallic phase presented dendritic structure. Mixing entropy and formation enthalpy can explain this behavior. After heat treatment at 1373K for 4 h, no new phase come into being but elements solute more fully. Compressive yield strength of the alloy gradually decreased from 1540MPa at room temperature to 371MPa at 1073K in as-cast state and decreased from 1483MPa at room temperature to 102MPa at 1073K after annealed. Comparing with the similar high entropy alloys, the structure combining silicide and continuous solid phase have a great benefit to the balance of strength and ductility.

• Periodical: Materials Science Forum (Volume 849)
• Pages: 76-84
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.849.76
• Online since: March 2016
• Authors: Yan Zhang, Yuan Liu*, Yan Xiang Li, Xiang Chen, Hua Wei Zhang
• Keywords: High Entropy Alloys, Induction Levitation Melting, Mechanical Properties, Microstructure, Silicide

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