An extremely stressed microscope

Materials World magazine
,
13 Jul 2018

A microscopy technique that can track microstructural changes in real time and when the material is exposed to extreme heat and stress has been developed by North Carolina State University, USA.

Afsaneh Rabiei, Professor of Mechanical and Aerospace Engineering at North Carolina State University, said, ‘This means we can see the crack growth, damage nucleation, and microstructural changes in the material during thermochemical testing, which are relevant to any host material. It can help us understand where and why materials fail under a wide variety of conditions – from room temperature up to 1,000˚C, and with stresses ranging from zero to two gigapascals.’

The team used the technique to ascertain the properties of alloy 709, a stainless steel alloy with potential for elevated temperature applications including nuclear reactor structures.

Rabiei continued, ‘Our microscopy technique allowed us to monitor void nucleation and crack growth along with all changes in the microstructure of the material throughout the entire process.’

The North Carolina team has chosen to focus their efforts on further analysing alloy 709, rather than discussing the potential future uses of the SEM technique.