Related Experiment Video
Updated: Aug 14, 2026

An Available Technique for Preparation of New Cast MnCuNiFeZnAl Alloy with Superior Damping Capacity and High Service Temperature
Published on: September 23, 2018
Cobalt-Free High-Entropy Alloys with Enhanced Strength-Ductility Synergy and Reduced Thermal Diffusivity
Yulin Li1, Zilong Hua2, Łukasz Kurpaska1
1NOMATEN Centre of Excellence, National Centre for Nuclear Research, Otwock05-400, Poland.
Abstract:
Developing advanced thermal barrier interlayers remains highly challenging due to the stringent requirements of simultaneously achieving high mechanical strength, sufficient ductility, and low thermal diffusivity. To address these limitations, a low-cost cobalt-free V10Cr15Fe30Mn15Ni30 HEA was designed. The alloy was cold-rolled to 80% thickness reduction. It was then annealed at 823-1223 K for 30 min. The annealed samples showed excellent strength-ductility synergy. They delivered an ultimate tensile strength over 1 GPa. The total elongation reached 15%. All annealed samples had low thermal diffusivity. Quantitative analysis revealed the strengthening mechanisms. Grain boundary strengthening and dislocation strengthening dominated yield strength increases below 1023 K. Grain boundary strengthening prevailed at and above 1123 K. This work offers new insights into how to leverage σ-phase precipitation for mechanical enhancement. It also tailors reduced thermal diffusivity through precipitate-matrix interface modifications. Refined grains, moderate dislocation density, σ-phase scattering, and severe lattice distortion work together. These effects increase the structural robustness and thermal barrier functionality of cobalt-free HEAs.
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
Metallic Solids
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
Valence Bond Theory
Mechanical Characteristics of Steel
The tension test is fundamental for determining tensile strength. In this test, a steel specimen is stretched using a gripping device until it breaks. The data collected during this test are used to...
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Bonding in Metals
