Acta Metallurgica Sinica (English Letters) ›› 2020, Vol. 33 ›› Issue (8): 1117-1123.DOI: 10.1007/s40195-020-01029-9

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Microstructure and Mechanical Behavior of CrFeNi2V0.5Wx (x = 0, 0.25) High-Entropy Alloys

Hui Jiang1,2, Tian-Dang Huang2, Chao Su1, Hong-Bin Zhang1, Kai-Ming Han1(), Sheng-Xue Qin1()   

  1. 1College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
    2Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province), School of Materials Science and Engineering, Dalian University of Technology, Dalian, 116024, China
  • Received:2019-10-14 Revised:2019-12-27 Online:2020-08-10 Published:2020-08-06
  • Contact: Kai-Ming Han,Sheng-Xue Qin

Abstract:

CrFeNi2V0.5Wx (x = 0, 0.25) alloys based on these parameters of mixing enthalpy (ΔHmix), mixing entropy (ΔSmix), atomic radius difference (δ), valance electron concentration, and electronegativity difference(Δχ) were designed and prepared. The microstructure and room-temperature mechanical behavior of both alloys were investigated. Compressive test results showed that the CrFeNi2V0.5W0.25 alloy had higher yield strength than that of the W-free CrFeNi2V0.5 alloy, although they all exhibited quite larger compressive plasticity (ε > 70%). Compression fracture surface of CrFeNi2V0.5W0.25 alloy revealed a ductile fracture in the face-centered cubic (FCC) phase and a brittle-like fracture in the σ phase. Moreover, tensile test results indicated that the CrFeNi2V0.5W0.25 alloy exhibited excellent mechanical property with an ultimate tensile strength of 640 MPa and a high tensile elongation of 15.7%. The tensile deformation mode of the FCC phase in the CrFeNi2V0.5W0.25 alloy is dominated by planar glide, relating to dislocation configurations, high-density dislocations, and dislocation wall. Therefore, dislocation slip plays a significant role in tensile deformation of CrFeNi2V0.5W0.25 high-entropy alloy. The higher strength of CrFeNi2V0.5W0.25 alloy is predominantly due to the solid solution strengthening of W element and σ phase precipitation strengthening. Combination of the higher tensile strength and plasticity suggests that the CrFeNi2V0.5W0.25 alloy can be a promising aerospace material.

Key words: High-entropy alloy, Microstructure, Mechanical property, Deformation behavior