Abstract
The potential of high-entropy alloys (HEAs) to exhibit an extraordinary combination of properties by shifting the compositional regime from the corners towards the centers of phase diagrams has led to worldwide attention by material scientists. Here we present a strong and ductile non-equiatomic HEA obtained after friction stir processing (FSP). A transformation-induced plasticity (TRIP) assisted HEA with composition Fe50Mn30Co10Cr10 (at.%) was severely deformed by FSP and evaluated for its microstructure-mechanical property relationship. The FSP-engineered microstructure of the TRIP HEA exhibited a substantially smaller grain size, and optimized fractions of face-centered cubic (f.c.c., γ) and hexagonal close-packed (h.c.p., ε) phases, as compared to the as-homogenized reference material. This results in synergistic strengthening via TRIP, grain boundary strengthening, and effective strain partitioning between the γ and ε phases during deformation, thus leading to enhanced strength and ductility of the TRIP-assisted dual-phase HEA engineered via FSP.
Highlights
High-entropy alloys (HEAs) represent a special class of materials that were orginaly designed to obtain a single-phase massive solid solution devoid of any secondary phases[1]
As discussed by Palanivel et al.[10], friction stir processing (FSP) leads to a homogenization of the microstructure and its local composition owing to the enhanced shear-related deformation-driven transport and mixing of the elements
After FSP we find that the same alloy showed ~8 and ~10% of h.c.p. at similar grain sizes of ~5.2 and 6.5 μm, respectively
Summary
High-entropy alloys (HEAs) represent a special class of materials that were orginaly designed to obtain a single-phase massive solid solution devoid of any secondary phases[1]. In this material a simultaneous increase in strength and ductility was obtained due to the engineered fraction and thermodynamic stability of the face-centered cubic (f.c.c., γ) and hexagonal close-packed (h.c.p., ε) phases in the microstructure through well designed composition and thermomechanical processing[3,4,6] While such microstructures and their effects associated with conventional thermomechanical processing on the deformation behavior in HEAs, including TRIP HEAs, have been investigated in detail, studies on severe plastic deformation, such as equal channel angular pressing (ECAP), high-pressure torsion (HPT) and friction stir processing (FSP), of HEAs and their effects on the mechanical properties[7,8,9] have been limited so far. FSP results provide a first overview of the alloy’s suitability for friction stir welding
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
