Microstructure and Mechanical Properties of the W-Ni-Co System Refractory High-Entropy Alloys

Abstract:

The elements Mo, Cr and V were added to the W-Ni-Co system high entropy alloys, the effects of these added elements on microstructure and mechanical properties of these alloys were studied. The alloys were produced by vacuum arc melting. The compositions were W_0.5Ni₂Co₂VMo_0.5, W_0.5Ni₂Co₂VCr_0.5 and W_0.5Ni₂Co₂CrMo_0.5 (denoted as Alloy 1, Alloy 2 and Alloy 3) respectively. The theoretical melting temperatures were higher than 2000 K. X-ray diffraction, SEM and energy dispersive spectroscopy (EDS) results indicated that the matrix of the alloys is face-centered cubic (FCC) solid-solution, the alloys showed dendrite crystal structure. Ni, Co elements were enriched in the dendrite areas, the W, Mo were enriched in the inter-dendrite regions ,while V, Cr elements were uniform distribution. The Vickers hardness of these alloys was 376.1 HV, 255.88 HV and 306.8 HV, respectively. The yield strength values (σ_0.2) of Alloy 1, Alloy 2 and Alloy 3 were approximately 1000MPa, 750MPa, 250MPa, respectively. The alloys show good compression plasticity deformation capacity at RT.

• Periodical: Materials Science Forum (Volume 816)
• Pages: 324-329
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.816.324
• Online since: April 2015
• Authors: Hui Jiang, Li Jiang, Yi Ping Lu*, Tong Min Wang, Zhi Qiang Cao, Ting Ju Li
• Keywords: Compression Property, Hardness, High-Entropy Alloys, Microstructure

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