What common defects does Magnetic Particle Inspection (MPI) aim to identify?

Magnetic Particle Inspection (MPI) is specifically designed to detect surface and near-surface discontinuities in ferromagnetic materials. This includes a variety of common defects such as cracks, fatigue failures, and inclusions. Each of these types of discontinuities can critically affect the integrity and performance of materials, particularly in structures that undergo stress or load.

Cracks may arise from manufacturing processes, operational fatigue, or even from improper handling or environmental factors. Similarly, fatigue failures typically occur due to repeated loading over time and can lead to catastrophic failures if not identified and addressed. Inclusions are non-metallic materials that can become trapped in the metal during the manufacturing process, weakening the material's performance.

While other choices may discuss different types of defects, none encompass the broad and specific range of discontinuities that MPI targets. Unlike wear and tear, which is more about the gradual degradation of materials and not limited to specific detectable flaws, MPI focuses on discrete defects that compromise the material's overall strength. Furthermore, defects only visible through microscopic examination or temporary defects lack the characteristics that MPI is designed to identify, as MPI is an effective non-destructive testing method for assessing surface anomalies without the need for extensive preparation or microscopic analysis.