Real-time microscopy helps characterise reactor metals

"Until now, you could look at a material's structure before exposing it to heat or load, then apply heat and load until it broke, followed by a microstructural observation. That means you'd only know what it looked like before and after loading and heating," said Afsaneh Rabiei, corresponding author of a paper on the work and a professor of mechanical and aerospace engineering at North Carolina State University (NC State).

"Our technique, which is called 'in situ scanning electron microscopy (SEM) heating and loading,' allows us to see the microscopic changes taking place throughout the process. You can see how cracks form and grow, or how microstructure transforms during the failure process. This is extremely valuable for understanding a material's characteristics and its behaviour under different conditions of loading and heating."

According to NC State, Rabiei developed the in-situ SEM technique for high temperatures and load as a means of conducting high throughput assessments of the behaviour of advanced materials. The goal was to be able to predict how a material responds under a variety of heating and loading conditions. The instrument can capture SEM images at temperatures up to 1,000 deg C and at stresses as high as two gigapascals (equivalent to 290,075psi).