Influence of zirconium addition on the microstructure, thermodynamic stability, thermal stability and mechanical properties of mechanical alloyed spark plasma sintered (MA-SPS) FeCoCrNi high entropy alloy

ABSTRACT

Equiatomic FeCoCrNi (Zr₀) and non-equiatomic FeCoCrNiZr_0.4 (Zr_0.4) high-entropy alloys (HEAs) were synthesised by mechanical alloying and spark plasma sintering. XRD analysis verified the formation of FCC and BCC solid solution phases in both alloys after 30 h of ball milling. While the SPS FeCoCrNi alloy contains both FCC and BCC solid solution phases, the FeCoCrNiZr_0.4 presents an FCC solid solution. The thermodynamic analysis showed that FeCoCrNiZr_0.4 is more stable with respect to the FeCoCrNi alloy. The phase stability of FeCoCrNiZr_0.4 was revealed up to ∼800°C. The shear strength and hardness of the FeCoCrNi HEA improved with Zr addition. Failure analysis of the shear punch tested samples revealed a ductile fracture with dimple structure for FeCoCrNi and a brittle fracture with a smooth featureless surface for FeCoCrNiZr_0.4.

KEYWORDS:

• High-entropy alloy
• mechanical alloying
• spark plasma sintering
• thermal stability
• mechanical behaviour

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Parisa Moazzen is a PhD student at Isfahan University of Technology, Department of Materials Engineering. His research interests focus on Hygh Entropy Alloys.

Mohammad Reza Toroghinejad is a PhD in Materials Engineering. His main research interest is severe plastic deformation, nano-structured materials, deformation and annealing textures, thermomechanical processing, hot-dip galvanizing, and coating texture. He is author of over 200 publications in International Journals.

Fathallah Karimzadeh received his Ph.D degree from Isfahan University of Technology. His research interests focus on synthesis, characterization, formation mechanism study and joining of nanostructured materials such as nano composites and nano particles for advanced applications. He is author of over 100 publications in International Journals.

Jef Vleugels's research interests focus on Processing of ceramics, Colloidal processing, Powder metallurgy, Electrophoretic deposition, Functionally graded materials, Coatings, Development and characterisation of ceramic matrix composites, Hardmetals and cermets, Electrically conductive ceramic composites, Chemical wear assessment, Cutting tools and wear parts. He is author of over 450 publications in International Journals.

Hamed Ravash is a Post Doctoral Researcher. His research interests focus on Advanced Ceramics and Powder Metallurgy. He is author of 3 papers in International Journals.

Pasquale Cavaliere is a PhD in Materials Engineering. His research interests focus on Thermal Spray Coatings, Powder Metallurgy, Ironmaking and Steelmaking. He is author of over 100 papers in International Journals.