What is it about?
We probably all remember the school demonstration where iron filings are found to line up in the magnetic field around a bar magnet. In a similar way what this work shows is that when the magnetic domains of carbon steel are loosened by stress, they reorient themselves (not surprisingly) in the local magnetic field which will (most likely) be the geomagnetic field. Measuring this change allows us to tell if the material is stressed or not.
Photo by Bryan Goff on Unsplash
Why is it important?
This is important because it provides a way to tell if carbon steel is under stress before cracks have started to appear.
Read the Original
This page is a summary of: Toward using the Villari effect for non-destructive evaluation of steel structures, Journal of Applied Physics, August 2023, American Institute of Physics,
You can read the full text:
The following have contributed to this page