High-Performance Corrosion-Resistant High-Entropy Alloys

NETL addressed the challenge of developing a design, manufacturing process and corrosion property validations for alloy compositions that consist of main constituent elements Ni, Fe, Cr, Co, and Mo. The alloy design methodology is based on the concept of high entropy of mixing and uses CALculation of PHAse Diagrams (CALPHAD) calculations. The resulting solid solution alloys have multiple principal elements that contribute to high entropy of mixing. The alloys consist of iron in large amount to reduce the cost. In addition to overcoming cost challenges, the new alloys can improve resistance to localized corrosion in aggressive service environments increasing the service life time of components.

The novelty of the high-entropy solid solution concept, optimized manufacturing route, improved corrosion resistance, and reduced cost constitute the main features of the innovation and approach of the technology to the identified challenges. The alloy compositions are new and have not been used before in industries or reported by others in the open literature. The manufacturing route is optimized for these alloys to achieve homogenization.

Advantages
The new alloys have use as more effective and lower cost coatings to protect metals and alloys from corrosion in extreme environments where corrosion is a major concern including sea water. The alloys certainly can be manufactured as bulk structural components that demand both high ductility and excellent corrosion resistance. In addition to overcoming cost challenges, the new alloys can improve resistance to localized corrosion in aggressive service environments increasing the service life time of components.