New Treatment Makes Superalloys Capable of Withstanding Heat Six Times Longer

In many ways, this has truly been the century of the engineer, as the professionals have lent their expertise and skills towards creating structures on the macro and micro level which are revolutionizing a number of industries.

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Nowhere has this been more apparent than in the creation of supermaterials. Superconductors, despite the healthy debate about their application, continue to emerge, and research and development (R&D) into the equally relevant superalloys, used in jet engines and adapted for even 3D-printed turbine blades, are in full swing.

Now, a group of researchers based at the Idaho National Laboratory (INL) believe they have created a superalloy that exceeds the capabilities of any superalloy around, one which they believe excels in "extending useful life by thousands of hours".

Strengthening the Process

To achieve their results, the researchers set out to change the heating and cooling methods related to the precipitates of the high-performance alloy, which fundamentally changed the nature of the microstructure.

The result: materials with six times greater heat withstanding properties. “We came up with a way to make a superalloy that is much more resistant to heat-related failures. This could be useful in electricity generators and elsewhere,” explains Subhashish Meher, INL materials scientist and lead author on the paper. 

Even more promising for the microstructures is that in computer simulation studies using the superalloy, the researchers projected that heat-induced failure would occur after about 20,000 hours. Many natural and man-made materials exhibit structure on more than one length scale; in some materials, the structural elements themselves have structure.

This structural hierarchy can play a major part in determining the bulk material properties. Based on the applied methods in the study, the team concluded that "hierarchical material design has the potential to influence the high-temperature stability of precipitate strengthened metallic materials". 

Benefits for the Industry

In terms of the advantages that the superalloys offer, one application the researchers point out is electrical generators, an obvious choice, as their superior heat tolerance and strength would allow them to hold up better than other materials which are currently in use.

They also argue that the material's properties can be adjusted, helping it perform differently in various applications. The current use is centered around its application in aerospace gas turbine engines, but this could change as well. 

What the work of the team seems to indicate is that with improved understanding of the effects of hierarchical material designs, materials can be synthesized, and controlled, in much more effective, dynamic and results-oriented ways. No doubt, it will have an impact down the road on a number of industries which rely on superalloys. 

“We are now better able to dial in properties and improve material performance,” Meher stated.

Details about the study appear in a paper, titled "The origin and stability of nanostructural hierarchy in crystalline solids", which was published November 16th in the Science Advances journal.