NIST improves stress testing

A team of scientists at the US National Institute of Standards and Technology (NIST) has developed a method of measuring material stress that takes more aspects of the part into account.

The materials scientists used a special X-ray machine at Argonne National Laboratory to look within a piece of material smaller than a cubic micrometer. 

The latest research builds on 2006 that developed a way to x-ray samples to measure stress in a single direction. By varying the wavelength, it is possible to generate different reflections that reveal the stress in more than one direction without changing the sample’s position. The NIST team also found that iy could get a clearer view by moving a small wire through the X-ray beam to block out distracting reflections that often come from other places in the sample. 

This approach has allowed the materials scientists to measure the ‘tensor,’ or full set of stresses, in cubic sections just 250 nm per side.

The next step is to develop an automated process to make all these measurements quickly.. 

‘We now have a method for measuring the full tensor,’ said NIST’s Lyle Levine, who worked on the project. ‘But it’s still slow and difficult. So the next step is to develop new technology that will make it much faster and easier for people to use.’

This story is reprinted from material from NIST, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.