Magnetic Particle Inspection for Surface & Subsurface Defect Detection
Non-destructive magnetic particle inspection services used to identify surface and near-surface cracks, seams, and discontinuities in ferromagnetic components used in aerospace, defense, medical, and industrial applications.
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Magnetic Particle Inspection Capabilities & Advantages
Magnetic particle inspection (MPI), also called magnetic particle testing (MT), is a non-destructive examination method used to detect defects in ferromagnetic materials such as carbon steel and alloy steels. By magnetizing the component and applying magnetic particles, inspectors can identify discontinuities that disrupt the magnetic field.
Spec & Capability Highlights
- Non-destructive inspection for ferromagnetic materials
- Detects surface and near-surface cracks and discontinuities
- Ideal for weldments, forgings, castings, and machined components
- Visible and fluorescent magnetic particle methods supported
- Performed by trained inspectors using calibrated equipment
- Supports aerospace, defense, and industrial specifications
How Magnetic Particle Inspection Works
Step 1 — Part Preparation
Components are cleaned to remove oils, scale, coatings, or contaminants that could interfere with defect detection.
Step 2 — Magnetization
The component is magnetized using electrical current or magnetic yokes to create a magnetic field within the material.
Step 3 — Magnetic Particle Application
Fine magnetic particles—either dry powder or suspended in liquid—are applied to the surface. These particles gather at magnetic flux leakage points caused by defects.
Step 4 — Inspection & Interpretation
Inspectors examine the component under visible or ultraviolet light depending on the particle type to identify indications of cracks or discontinuities.
Step 5 — Documentation & Certification
Inspection results are documented and certified for traceability and specification compliance.
Magnetic Particle Inspection Methods
Visible Magnetic Particle Inspection
Uses colored particles that are visible under normal lighting conditions and are commonly used for general industrial inspections.
Fluorescent Magnetic Particle Inspection
Uses fluorescent particles viewed under ultraviolet light to provide higher sensitivity and improved defect visibility.
Why Use Hydrostatic Pressure Testing?
Structural Integrity Verification
Hydrostatic testing confirms that components can safely withstand operating pressures without failure.
Leak Detection Under Load
Applying pressure reveals leaks that may not be visible during static inspection.
Enhanced Safety
Using liquid instead of gas significantly reduces stored energy and testing risk.
Why Work With MIL for Magnetic Particle Inspection?
Experienced NDT Inspectors
MIL’s inspection personnel are trained to identify critical indications in components used in demanding industrial environments.
Reliable Detection for Critical Hardware
MPI is particularly effective at identifying cracks in ferromagnetic parts where early detection is essential for safety and reliability.
Integrated NDT & Finishing Services
Magnetic particle inspection can be performed alongside metal finishing, welding, coatings, and other NDT methods within the same facility.
Specification-Driven Inspection
Processes are performed according to customer drawings, industry standards, and applicable inspection procedures.
Applications & Industries Served
Component Types
- Forged and machined steel components
- Welded assemblies and structural parts
- Pressure vessels and mechanical hardware
- Aerospace and defense components
- Industrial machinery and heavy equipment parts
Industries
- Aerospace & defense
- Industrial manufacturing
- Energy and power generation
- Heavy equipment and machinery
- Precision manufacturing and OEM production
Frequently Asked Questions About Hydrostatic Pressure Testing
MPI detects surface and near-surface cracks, seams, laps, inclusions, and other discontinuities in ferromagnetic metals.
Magnetic particle inspection is suitable for ferromagnetic materials such as carbon steels, alloy steels, and some nickel-based alloys.
No. MPI is a non-destructive testing method that does not alter or damage the part when properly performed.
MPI is most effective for surface and near-surface defects but cannot detect deep internal discontinuities.
Penetrant testing can be used on many materials, while MPI is limited to ferromagnetic metals but can detect near-surface defects not visible with penetrant methods.
Yes. MPI is often performed alongside penetrant testing, radiography, welding inspection, and metallurgical testing to provide comprehensive quality assurance.
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