Failure Analysis of a Shot-Peened Component

A comprehensive scanning electron microscope(SEM) survey of the fracture surfaces of an aircraft main landing gear shock strut piston showed that improper shot peening contributed to the initiation of the anamolous fatigue failure.

SEM photographs of the suspect-origin regions and the surrounding areas were analyzed. The photographs are presented, along with a detailed description of the regions observed. Failure mechanism is discussed, and causes of fracture origin explored.