Laser rust removal is an entirely different process than paint removal. Typical steel rust is a combination of iron oxides such as ferric oxide, Fe2O3, ferrous oxide, FeO, and magnetite Fe3O4. These are partially transparent to NIR radiation, resembling semiconductors. However, rust is far from being a homogenous or continuous layer.
This is part five of a five part series. You can find links to the previous articles below.
Figure 3 : Sketches of 3 modeled levels of rust development
A model describing the different levels of rust and relevant surface structuring is depicted in Figure 3.
For Level 1 type rust, the rust only exists as surface layers and occasionally creates shallow pits of maximum 50 μm depth with the edges of the pits in line of sight to a single reference point above the surface.