High Entropy Alloys

High Entropy Alloys

The conventional alloys like steel, superalloys, etc. are based on one principal element with alloying additions done to improve their structural and functional properties. In contrast, high entropy alloys (HEAs) are multicomponent alloys having constituents in equiatomic or near equiatomic ratios. They exhibit simple solid solution structures owing to their high configurational entropy. HEAs have been shown to possess good creep strength, excellent oxidation corrosion and wear resistance, high hardness, superior thermal and chemical stability and good magnetic properties. Therefore, HEAs are being explored for variety of applications and have gathered attention of scientific community worldwide.

Many groups across the nation are actively working on various facets of high entropy alloys. Click here for more information.

Our group studies diverse aspects of high entropy alloys such as phase prediction using thermodynamic and kinetic principles, fundamental properties like diffusion, magnetism, their applicability as high temperature coating material and their oxidation and corrosion behaviour.

Thermodynamic phase predictions in High entropy alloys - The high configurational entropy resulting from the sort of compositions in HEAs was expected to stabilize simple solid solutions in microstructure. But, exceptions to such behaviour were reported in several cases. Therefore, search for the rules governing the phase formation in HEAs has become a major academic interest. Read More

Kinetic phase predictions in High entropy alloys - Phase prediction in high entropy alloys (HEA) is a prime challenge for materials engineers as the final phase determines the properties of the HEA. Several approaches depending on thermodynamic, topological or electronic properties of constituent elements have been explored so far without much success. Read More

Diffusion in High entropy alloys : Sluggish diffusion has been put forward as one of the core effects in high entropy alloys (HEAs) and is believed to be responsible for their high thermal stability and creep resistance. Slower diffusion is also presumed to play a role in phase evolution and promote formation of nano-precipitates and amorphous phases in many HEAs. However, till date, reports on diffusion in HEAs are scarce and it has only been measured using interdiffusion approach. Read More
 
Lavanya - Refractory High entropy alloys
 
High entropy alloy coatings - My work is centered around finding a HEA composition that can be a possible alternative to present day bond coats used in thermal barrier coatings. Traditionally, TBCs are thermally insulating ceramics bonded onto superalloy components via metallic bond coats, which are usually Ni based dual phase alloys having sufficient Al to form an oxidation resistant alumina layer during service. Read More
 
Rahul - Oxidation behavior of High entropy alloys
 
Thermal stability of High entropy alloys - Properties of materials play a major role in any application. The properties of a material depend on the structure. The ability of retaining those properties depends on the stability of that structure in different environments like high/low temperature, corrosive environment, heavy loads and high speed applications. Read More
 
Raghavendra - Magnetic High entropy alloys