Strong and ductile materials that have high resistance to corrosion and hydrogen embrittlement are rare and yet essential for realizing safety-critical energy infrastructures, hydrogen-based industries, and transportation solutions. Here we report how we reconcile these constraints in the form of a strong and ductile CoNiV medium-entropy alloy with face-centered cubic structure. It shows high resistance to hydrogen embrittlement at ambient temperature at a strain rate of 10−4 s−1, due to its low hydrogen diffusivity and the deformation twinning that impedes crack propagation. Moreover, a dense oxide film formed on the alloy’s surface reduces the hydrogen uptake rate, and provides high corrosion resistance in dilute sulfuric acid with a corrosion current density below 7 μA cm−2. The combination of load carrying capacity and resistance to harsh environmental conditions may qualify this multi-component alloy as a potential candidate material for sustainable and safe infrastructures and devices.
1 November 2021 in Journal of the Electrochemical Society
For a long time, the corrosion problem of materials has been an essential factor in restricting high-tech and national economic development. As an effective means of corrosion protection, surface coatings have drawn extensive attention in the field of material corrosion. Performance improvement and a new composition system of high-entropy alloys (HEAs) have made HEA coatings a research hotspot. HEA coatings inherit the “four core effects” of bulk HEAs, especially high entropy and sluggish diffusion, making high-quality coatings exhibit outstanding corrosion resistance. At present, many reports have focused on the performance of HEA coatings in the field of severe corrosion environments. This article reviews the process parameters and different element contents on the corrosion resistance of HEA coatings in recent years. This paper describes the advantages and excellent corrosion resistance of HEA coatings, including the preparation methods and classification of HEA coatings. Moreover, exploration of the corrosion behavior and the mechanism of HEA coatings are described, and the influence of passivation behavior and microstructure change on the corrosion resistance of HEA coatings are discussed. Finally, the prospect of research on corrosion-resistant HEA coatings is proposed, and possible future research directions and ideas are suggested.
28 September 2022 in Materials Chemistry and Physics