Magnetic Particle Testing

(MT)
By
Ir. Dr. Eliza Binti M. Yusup

1
OUTLINE

1. Introduction to Magnetic Particle Testing (MT)

2. Fundamental of MT
3. Magnetism
4. Magnetization
5. Standardization and Calibration
6. Interpretation and evaluation
7. Application and limitation of MT

2
DEFINITION OF MT

1) Inducing a magnetic field in a ferromagnetic material ---- dusting

the surface with iron particles (either dry or suspended in liquid).
2) Surface and near-surface flaws --- force some of the field to leak out
at the surface.
3) Iron particles attracted and concentrated at sites of the magnetic
flux leakages.
4) Produces a visible indication of defect on the surface

3
INTRODUCTION OF MT

https://www.youtube.com/watch?v=93sRATwdHo4

https://www.indiamart.com/proddetail/magnetic-particle-dry-method-testing-12981229897.html 4
INTRODUCTION OF MT

https://www.spacescienceservices.com/new-blog/2017/1/4/basic-steps-for-magnetic-particle-examination 5
INTRODUCTION OF MT

https://www.tuv.com/greater-china/en/magnetic-particle-inspection-(mpi)-services.html

https://www.theegroup.co.uk/etest
6
INTRODUCTION OF MT

https://www.victor-aviation.com/NDT-Production-Services/Magnaflux-Inspection.php 7
INTRODUCTION OF MT

https://www.victor-aviation.com/NDT-Production-Services/Magnaflux-Inspection.php 8
INTRODUCTION OF MT (Class activity)

What do you observed from above images of MT technique?

1.
2.
3.
4.
5.

9
VIDEO – INTRODUCTION OF MT

https://www.youtube.com/watch?v=93sRATwdHo4 10
VIDEO – INTRODUCTION OF MT

https://www.youtube.com/watch?v=L8ZNs5BvuoA 11
VIDEO – INTRODUCTION OF MT

https://www.youtube.com/watch?v=dQoB7jpxSe8&t=78s 12
APPLICATION AND LIMITATION OF MT (CLASS ACTIVITY)

Based on the above videos, identify the advantages and

disadvantages of MT method?(i.e: tage inspections, image output, material etc..)
Advantages
1.
2.
3.

Disadvantages
1.
2.
3.
13
FUNDAMENTAL OF MT - Current

I = Q/t
where Q is the net charge flowing across the section in time t

Liquid Penetrant and Magnetic Particle Testing at Level 2, Manual for the Syllabi Contained in IAEA-TECDOC-628, “Training Guidelines in Non-destructive Testing Techniques” Page 179-201 14
FUNDAMENTAL OF MT - Voltage

Liquid Penetrant and Magnetic Particle Testing at Level 2, Manual for the Syllabi Contained in IAEA-TECDOC-628, “Training Guidelines in Non-destructive Testing Techniques” Page 179-201 15
FUNDAMENTAL OF MT - Resistance

Liquid Penetrant and Magnetic Particle Testing at Level 2, Manual for the Syllabi Contained in IAEA-TECDOC-628, “Training Guidelines in Non-destructive Testing Techniques” Page 179-201 16
FUNDAMENTAL OF MT – Leakage Field

In the absence of a crack or discontinuity, the lines of

the magnetic field pass from one end
of the object to the other without breaking through
the surface.

If very small ferromagnetic particles were sprinkled

over the surface of the object shown in Figure 6.8
they would be attracted and held by the leakage field
in the region of the discontinuity.

Even though the discontinuity may be too small to be visible to the unaided eye, the magnetic
field may still be disturbed enough to attract a sufficient number of fine particles to present a
visible indication.

These particles may be colored to make them more visible and thus make the inspection
method more sensitive.

Liquid Penetrant and Magnetic Particle Testing at Level 2, Manual for the Syllabi Contained in IAEA-TECDOC-628, “Training Guidelines in Non-destructive Testing Techniques” Page 179-201 17
FUNDAMENTAL OF MT

Interaction of Magnetic Field Lines

with discontinuity in a Component

The direction of magnetic field lines

represented by the alignment of iron
filings sprinkled on paper placed above
a bar magnet

https://worldofndt.com/introduction-to-magnetic-particle-testing/ 18
FUNDAMENTAL OF MT – Internal Discontinuity

(Internal discontinuity) A discontinuity that lies deep within the object, however, may not
disturb the lines of force sufficiently to cause them to emerge from the surface. In this case
there would be no attraction of the particles and no surface indication Figure 6.9(b).

Liquid Penetrant and Magnetic Particle Testing at Level 2, Manual for the Syllabi Contained in IAEA-TECDOC-628, “Training Guidelines in Non-destructive Testing Techniques” Page 179-201 19
FUNDAMENTAL OF MT – Orientation Discontinuity

(Orientation discontinuity) A discontinuity oriented parallel to the magnetic field in the object
will have far less effect on the field than a discontinuity perpendicular to the field.

Since the discontinuity at “b” in Figure 6.10 disrupts the magnetic field very little, there would
be few if any magnetic particles attracted to it. Discontinuity “a” however causes
considerable disruption of the magnetic field causing some lines of flux to leave the
material. Magnetic particles would be more readily attracted to the surface near “a”
marking the discontinuity more detectable.

The test sensitivity will then be best for discontinuities oriented 90o to the field direction,
with tolerable results possible down to about 75o

Liquid Penetrant and Magnetic Particle Testing at Level 2, Manual for the Syllabi Contained in IAEA-TECDOC-628, “Training Guidelines in Non-destructive Testing Techniques” Page 179-201 20
FUNDAMENTAL OF MT

Liquid Penetrant and Magnetic Particle Testing at Level 2, Manual for the Syllabi Contained in IAEA-TECDOC-628, “Training Guidelines in Non-destructive Testing Techniques” Page 179-201 21
STANDARD USE IN MT

Some of the organizations such as American Society of the Mechanical

Engineers (ASME), American Welding Society (AWS), American Society
for Testing and Materials (ASTM), the Society of Automotive Engineers etc.

Liquid Penetrant and Magnetic Particle Testing at Level 2, Manual for the Syllabi Contained in IAEA-TECDOC-628, “Training Guidelines in Non-destructive Testing Techniques” Page 249 22
STANDARD USE IN MT

(E2297-15) Standard Guide for Use of UV-A and Visible Light

Sources and Meters used in the Liquid Penetrant and Magnetic
Particle Methods

E125-63(2013) Standard Reference Photographs for Magnetic

Particle Indications on Ferrous Castings

ASTM Volume 03.03 Nondestructive Testing (I): C1331 – E2373 23

CALIBRATION OF MT

https://www.youtube.com/watch?v=6PAERlvMDi8 24
CALIBRATION PROCESS (Magnaflux – 5 steps)
Magnetic Particle Equipment in reference to ASTM E1444, ASTM
E3024, ISO 9934, or Nadcap AC7114/2
by David Geis, Product Manager, and Brian Batteiger, NDT Services Manager

Step 1: Verify your standards

Step 2: Ammeter accuracy
Step 3: Equipment repeatability
Step 4: Shot Time
Step 5: Quick Break for 3-phase FWDC units only

https://www.magnaflux.com/Magnaflux/Resources/Blog/Calibrate-MPI-Equipment 25
CALIBRATION CERTIFICATION OF MT (TemaFlux)

All calibration certificate for magnetic particle inspection

equipment refers to Accredita or UKAS certificated references,
according to ASME Sect. V Art.7. The calibration procedures
and management system is according ASME III NCA 3850.
TemaFlux works under a quality management system certified
ISO 9001:2008.
https://www.temaflux.com/en/calibration-certification-mpi-equipment/ 26
BASIC OVERVIEW OF NDT METHODS

Group Revision Assignment (Guided Learning_NF2F SLT)

CHAPTER 2 (10/60)
Introduction of MT (History, how to be qualified MT inspector etc)
Code of Standard in MT
Application in MT (Methods and techniques of MT)
Advantages / Limitation of MT
Basic theory of MT
Interpretation and evaluation of MT
Sample of question / tutorial related to MT

* Additional video clip links are encouraged.

Source: Website 27
RESEARCH IN MT (90’s)

Source: Science Direct 28

RESEARCH IN MT (2000’s)

Source: IEEE 29
Thank You
30