What inspection method is commonly used to detect metal fatigue in engines?

The method of inspection that is commonly used to detect metal fatigue in engines is magnetic particle inspection. This non-destructive testing technique is particularly effective for identifying surface and near-surface discontinuities in ferromagnetic materials, which are prevalent in many engine components.

When metal fatigue occurs, it often leads to the development of cracks or other defects that can be detected at the surface. Magnetic particle inspection involves the application of a magnetic field to the component in question, followed by the application of fine iron particles. If there are any surface defects, the magnetic field will cause the particles to cluster at these areas, revealing the presence of fatigue or cracks. This method is valued for its sensitivity to very small defects, making it an essential tool in the maintenance and inspection of aircraft engines.

Other inspection methods, while useful in their own right, are not primarily aimed at detecting metal fatigue. Visual inspection, for instance, is limited to surface observations and may not detect subsurface cracks. Ultrasonic testing relies on sound waves to find defects but is more complex and typically used for thickness measurements rather than fatigue. X-ray inspection is excellent at revealing internal structures but is not as effective for surface defects related to metal fatigue. Thus, magnetic particle inspection stands out as the most relevant