This superalloy can stand the heat

Having the right tool for the job is key for getting it done quickly and easily, at least that’s what my dad always said. “It’s all about having the right tool for the job,” he’d tell me.  

When it comes to process automation, having the right tool, or most effective elements, in place can be key to process optimization. In order to help high-heat operations, researchers at Idaho National Laboratory (INL), a U.S. Department of Energy national laboratory and a leading center for nuclear energy research and development, have found a way to extend the useful life of “superalloys” by thousands of hours, which could benefit performance for electrical generators and nuclear reactors.

“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,” said Subhashish Meher, an INL materials scientist and lead author of a new Science Advances paper describing the research, in a statement.

By heating and cooling the superalloy in a specific way, the microstructure within it can withstand high heat more than six-times longer than an untreated counterpart, the research found. In fact, computer simulations have suggested that the treated superalloy could resist heat-induced failure for 20,000 hours, compared with the generally expected 3,000 hours.

Breaking down the research

Scientists at INL have been studying nickel-based superalloys because they can withstand high heat and extreme mechanical forces, which makes them ideal for electricity-generating turbines and high-temperature nuclear reactor components. Previously, research found that performance of superalloys could be improved if the material structure repeats from very small to very large sizes.

The hierarchical microstructure of a superalloy consists of a metallic matrix with precipitates. Within these precipitates are even finer particles that are the same composition as the matrix around them. Think nested boxes.

Along with his co-authors, Meher studied how the precipitates formed within a superalloy and how the structure withstood extreme heat and other treatments. From these studies, the team found that with the right amounts of heating and cooling, the precipitates became two or more times larger, which created the desired microstructure. Digging deeper, when subjected to extreme heat, the larger precipitates lasted significantly longer.

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

This research appeared Nov. 16 in Science Advances, “The origin and stability of nanostructural hierarchy in crystalline solids.”