Education/Definitions

Fatigue Striations

Marks left on a fatigue fracture surface as a result of the advance or growth of the fatigue crack resulting from one load application.  To visualize a single fatigue striation or even a series of fatigue striations requires extremely high magnifications.  Individual striations are often visible at high magnifications in a scanning electron microscope (SEM). The yellow marker pictured below traverses approximately 13 fatigue striations 9.8 microinches (9.8 X 10-6 inches or 0.0000098 inches).

SEM example of fatigue striations
Photograph A  Example of fatigue striations
 as seen through a SEM at a magnification of
 10,000x.

 


Updated 7/12/10