Magnetic Particle Inspection Training Course

Magnetic Particle Inspection Training Course
Magnetic Particle Inspection is a non-destructive testing method used for defect detection.
MPI is a fast and relatively easy to apply and part surface preparation is not as critical as it
is for some other NDT methods. These characteristics make MPI one of the most widely
utilized non-destructive testing methods. MPI uses magnetic fields and small magnetic
particles, such as iron filings to detect flaws in components.
Because magnetization of certain metals is possible, it is possible to reveal discontinuities by

using a medium (iron powder) having magnetic attraction. The medium is applied to the
surface of the test object after or during induction of a magnetic field. The sketch below
shows a build-up of the magnetic particle medium over the discontinuity in the magnetized
part. Magnetic Particle Testing is a relatively easy and simple test method that can be
applied at various stages of manufacture and processing operations. The objective of
Magnetic Particle Testing is to insure product reliability by providing means of:
The only requirement from an inspect ability standpoint is that the component being
inspected must be made of a ferromagnetic material such iron, nickel, cobalt, or some of
their alloys. Ferromagnetic materials are materials that can be magnetized to a level that
will allow the inspection to be effective. The method is used to inspect a variety of product
forms such as castings, forgings, and weldments. Many different industries use Magnetic
Particle Inspection for determining a component's fitness-for-use. Some examples of
industries that use magnetic particle inspection are the structural steel, automotive,
petrochemical, power generation, and aerospace industries. Underwater inspection is
another area where magnetic particle inspection may be used to test items such as offshore
structures and underwater pipelines.
Magnetic particle testing or MPT is a nondestructive testing method for locating surface
and near surface discontinuities in ferromagnetic materials. It depends for its operation on
the fact that when the material or part under test is magnetized, discontinuities that lie in a
cause leakage field to the direction of the magnetic field will cause a leakage field to be
formed at and above the surface of the part. The presence of this leakage field, and
therefore the presence of the discontinuity, is detected by the use of finely divided
ferromagnetic particle applied over the surface, some of the particle being gathered and
held by the leakage field. This magnetically held collection of particle forms an outline of the
discontinuity and generally indicates its location, size, shape and extent. Magnetic particles
are applied over a surface as dry particles, or as wet particle in a liquid.
Ferromagnetic materials include most of the iron, nickel and cobalt alloys. These materials
lose their ferromagnetic properties above a characteristic temperature called the Curie point
which is approximately 760◦ C for most of the ferromagnetic material.
Applications
The principal industrial uses of magnetic article testing are final inspection, receiving
inspection, in process inspection and quality control, maintenance and overhaul in the
transportation industries, plant and machinery maintenance and inspection of large
components.
Limitations
Thin coatings of paint and other non-magnetic coverings, such as plating; adversely affect
sensitivity of magnetic particle inspection. Other limitations are:
1. Magnetic particle inspection methods will work only on ferromagnetic materials.

2. For best results, the magnetic field must be in a direction that will intercept the principle
plane of the discontinuity. Sometimes this requires two or more sequential inspections. With
different magnetizations.
3. Demagnetization following magnetic particle testing is often necessary.
4. Post cleaning to remove remnants of the magnetic particle clinging to the surface may be
required after testing and demagnetization.
5. Exceedingly large currents sometimes are required for very large parts.
6. Care is necessary to avoid local heating and burning of finished parts or surface at the
points of electric contact.
7. Although magnetic particle indications are easily seen, experience and skill in interpreting
their significance are needed.
Magnetic particle inspection facilities

1. Specialized magnetic particle inspection equipments for Aerospace NDT applications
2. Modern high amperage magnetic particle testing equipments including electromagnetic
yokes
3. Powerful mobile type of prod equipments
4. 6000 amperes stationery wet horizontal type equipments for inspection of mass production
components, coils, solenoids, central conductors with AC, HWDC and FWDC facilities.
5. High intensity black light kits for fluorescent inspection and demagnetizing equipments
6. Magnetic particle testing professionals are qualified and certified to MT Level I, II as per
ASNT recommended practice SNT-TC-1A, IS:13805 certified by Indian Society for
Nondestructive testing (ISNT) and are approved by leading third party inspection authorities
7. Experienced in house ASNT NDT Level III consultants and experts for providing techniques
establishment, procedure preparation, approval and consultancy services.
8. ASNT NDT Level III trainers for conducting in house or external NDT Level 1, 2 training and
certification courses on Magnetic particle testing and other NDT inspection methods. Read
more about Magnetic Particle testing personnel Certifications.
9. Strong team of NDT professionals to provide magnetic particle testing services across India
10. Sales and Supply of magnetic particle inspection (MPI), powders, consumables and other
accessories. Read more about sales of Magnetic particle inspection equipments
Magnetic Particle Testing (MT)
This NDT method is accomplished by inducing
a magnetic field in a ferromagnetic material
and then dusting the surface with iron particles
(either dry or suspended in liquid). Surface and
near-surface flaws disrupt the flow of the
magnetic field within the part and force some
of the field to leak out at the surface. Iron
particles are attracted and concentrated at
sites of the magnetic flux leakages. This produces a visible indication of defect on the
surface of the material. The images above demonstrate a component before and
after inspection using dry magnetic particles.

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Magnetic Particle Inspection Training Course

Because magnetization of certain metals is possible, it is possible to reveal discontinuities by

1. Magnetic particle inspection methods will work only on ferromagnetic materials.

Magnetic particle inspection facilities

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