Our Terms & Conditions | Our Privacy Policy
Researchers at the Canadian Nuclear Laboratories (CNL) are studying a special type of material called a high entropy alloy (HEA) made using different metals to withstand high temperatures and radiation from nuclear reactors.
The researchers hope their material will eventually replace stainless steel, currently used for these applications.
As the world looks to move away from fossil fuels, alternative energy sources such as nuclear power are poised to take the lead. While a proven system to prevent carbon emissions, nuclear energy comes with its concerns of safety.
The extreme reaction conditions inside the nuclear reactor are an engineering challenge, and researchers are looking for ways to mitigate risks with newer technology and materials.
While stainless steel has long been the mainstay for building nuclear reactors, researchers are now looking for better materials that can withstand these extremes. High entropy alloys are one such material.
What is a high entropy alloy?
Unlike conventional alloys made up of two metals and additions of other metals in minor concentrations, high entropy alloys (HEA) consist of five or more metals mixed in more or less equal atomic concentrations.
The increased constituent elements result in high mixing entropy, eventually stabilizing into a simple solid solution phase, often a cubic structure. This leads to a distorted lattice structure, which gives HEAs their unique properties, such as high strength, ductility, and corrosion resistance, among others.
Previous research has shown that HEA are also resistant to radiation, but how they develop this resistance is not well understood.
Studying HEAs with light
A research team led by Qiang Wang, a material scientist at CNL, deployed the ultrabright synchrotron light at the Canadian Light Source at the University of Saskatchewan to study a HEA made from iron, manganese, chromium, and nickel.
“It has to be stable, so it won’t change the microstructure at high heat, and have a certain resistance to irradiation,” explained Wang on the choice of the material in a press release. “That’s why we chose this material. And also because it is reasonably easy to manufacture.”
The researchers exposed the HEA to high-energy protons at temperatures of 752 Fahrenheit (400 degrees Celsius) and 1112 Fahrenheit (600 degrees Celsius), while also exposing them to various amounts of radiation, and used the synchotron’s X-rays to study the effects on the HEA.
The team observed small plate-shaped defects in the HEA called Frank Loops at lower temperatures that grew in number at larger temperatures. As the temperatures increased, the metals began to separate, with some areas losing manganese, while others gained iron and nickel. This gave researchers a better idea of how the HEA behaves under extreme conditions.
While the HEA performed better than stainless steel, Wang tempered down expectations from the research. “We did find some advantages and some things we didn’t expect to happen, so obviously this material needs to be better studied to understand the applications fully.”
“It’s still not code approved in the nuclear industry, so we don’t know exactly what it will be used for, which is why we are testing the material to see if it can meet those qualifications,” concluded Wang in the press release.
Images are for reference only.Images and contents gathered automatic from google or 3rd party sources.All rights on the images and contents are with their legal original owners.
Aggregated From –
Comments are closed.