Microstructure and mechanical properties of hot isostatic pressed tungsten heavy alloy with FeNiCoCrMn high entropy alloy binder

Abstract

Microstructural development and mechanical properties of tungsten heavy alloy, WHA, with FeNiCoCrMn high entropy alloy, HEA, binder were investigated and compared to conventional WHA using Fe–Ni binder. Both WHAs, with HEA and conventional Fe–Ni binders, were fabricated by hot isostatic pressing at a temperature of 1450 °C in an argon environment. Scanning electron microscopy revealed that WHA with HEA and conventional binders possessed uniform and well-refined microstructures. Energy dispersive spectroscopy and X-ray diffraction, XRD, spectroscopy validated the formation and composition of HEA, existing as a skeletal network surrounding tungsten grains. HEA binder exhibited an overall increase of 42% in micro Vickers hardness values. Furthermore, hardness values of the tungsten heavy alloy were also seen to rise when fabricated with HEA binder. However, WHA sample with HEA binder was seen to undergo faster strain hardening and a premature failure, leading to lower values of ultimate strength and reduced ductility.

Keywords

• Tungsten heavy alloys
• High entropy alloys
• Hot isostatic pressing
• Liquid phase sintering