Magnetic Particle Testing (MT) Services
Magnetic Particle Testing detects surface and near-surface defects in ferromagnetic materials using magnetic fields and iron particles.
What is Magnetic Particle Testing?
Magnetic Particle Testing (MT/MPI) is used to detect surface and near-surface discontinuities in ferromagnetic materials such as steel, iron, nickel, and cobalt alloys. The method works by magnetizing the test area and applying fine ferromagnetic particles (dry or in suspension) to the surface. Discontinuities cause magnetic flux leakage that attracts particles, forming visible indications that outline the defect.
How MT Works
Test piece is magnetized using direct or indirect magnetization
Discontinuities disrupt the magnetic flux flow
Flux leakage at defects attracts ferromagnetic particles
Visible or fluorescent particles form indications at defects
Applications of Magnetic Particle Testing
Advantages
- Rapid and relatively simple to perform
- Can detect defects through thin coatings
- Immediate results
- Portable equipment available
- Relatively inexpensive
- Can detect near-surface defects
Limitations
- Only works on ferromagnetic materials
- Surface preparation may be required
- Demagnetization needed after testing
- Limited depth of detection
- Proper magnetization direction critical
Applicable Standards & Codes
Industries Using MT
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Other NDT Methods
Ultrasonic Testing uses high-frequency sound waves to detect internal flaws, measure material thickness, and characterize material properties.
Learn moreRadiographic Testing uses X-rays or gamma rays to create images of a component's internal structure, revealing hidden defects.
Learn moreLiquid Penetrant Testing reveals surface-breaking defects by applying a colored or fluorescent dye that seeps into cracks and discontinuities.
Learn moreEddy Current Testing uses electromagnetic induction to detect surface and near-surface flaws in conductive materials.
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