Improving mechanical properties (glass bead blasting)
After the object has been cleaned of contaminants, glass balls of 40 – 70 µm and 100 – 200 µm are fired at the surface using relatively low pressure compressed air.
This creates a cold deformation (reinforcement) in the surface, making it smoother and harder. This also increases the resistance to various types of corrosion, such as stress corrosion and corrosion fatigue.
Characteristic of the glass bead blasting is that it reduces the roughness of the surface. The height of the tops and the depth of the valleys remain approximately the same after blasting. However, the surface is smoother and less dirt will adhere to it. Compared to a mechanically polished surface, the roughness appears to be greater on a macro scale. However, on a micro scale, the roughness is comparable to a polished surface and this is important for good adhesion.