7.1.5 Crack / Scratch Propagation

An AFM is ideal for studying crack propagation in surfaces because the AFM gives great contrast on flat samples. If the crack is longer than the FOV of the AFM scanner, it may be necessary to measure several AFM images in succession. Measuring the images can be facilitated if the AFM stage has a motorized stage that can be programmed to measure the entire crack. Also, it is often possible to place a device for creating stresses and strains in materials directly in the AFM stage. In such a case, direct images of crack formation are measurable.

7.1.6 Coatings

Many types of coatings on surfaces are directly measurable with an AFM. The only requirement is that the coating surface roughness be less than the dynamic range of the Z piezo in the AFM. The thickness of coating can be measured with a cross section or by having a region of the sample surface that has a transition to the coating.