What Are The Advantages of Magnetic Particle Inspection?

NDT training institute in Hyderabad, is a reputed institute which prepares students for different kinds of training related to engineering services. Here the students pursue courses in different backgrounds like ultrasonic testing, radiography testing and magnetic particle testing. They prepare students to get on the job oriented training programs in industries such as, fabrication, manufacturing, fabrication,  automobile, aerospace, power plants, oil and gas sector and inspection companies. They also offer courses in organizational behavior and communication skills. Both NDT institutes in Hyderabad and NDT institute in Vishakhapatnam provide students a sound knowledge of core engineering sector.

BASIC PRINCIPLE OF MAGNETIC PARTICLE INSPECTION –

NDT training in Hyderabad opens up an enormous scope for students to get NDT jobs in Hyderabad. Out of all the premier courses offered at NDT training institute in Hyderabad, is the magnetic particle inspection. It is a practical training course that could be pursued by engineering students as well as working candidates. Magnetic particle testing is used mostly in inspection of mechanically welded heavy metals which is used in various sectors like automobiles, aviation, maintenance, power plants and hydroelectricity. It is used to detect discontinuities and leakage in ferromagnetic substances of the heavy metals manufacturing sector. .

 It has a wide scope of knowledge and usage as of today. Let’s learn in details about this valuable course and its functionality.

The magnetic particle inspection (MPI) is a relatively simple concept. The main principle behind this magnetic particle inspection is magnetic flux leakage.

For example take a bar magnet. It has a magnetic field in and around the bar magnet. Any place that a magnetic line of force exits or enters the magnet is called a pole. A pole where a magnetic line of force exits the magnet is called a north pole and a pole where a line of force enters the magnet is called a south pole. If we break the bar magnet at the centre, it will result in two bar magnets, with north and south poles on each end of the magnets. There is no isolated pole in the magnets.

If the magnet is just cracked but not broken completely in two, a north and south pole will form at each edge of the crack. The magnetic field exits the North Pole and reenters into the South Pole. The magnetic field spreads out when it encounters the small air gap created by the crack, because the air cannot support as much magnetic field per unit volume as the magnet can. When the field spreads out, it appears to leak out of the material and, thus, it is called a flux leakage field.

If iron particles are sprinkled on a cracked magnet, the particles will be attracted to and cluster not only at the poles but also at the edges of the crack. This cluster of particles is much easier to see than the actual crack and this is the basis for magnetic particle inspection.

The first step in a magnetic particle inspection is to magnetize the component that is to be inspected. If any defects on or near the surface are present, the defects will create a leakage magnetic field. After the component has been magnetized, iron particles are applied to the surface of the magnetized part. The particles will be attracted and cluster at the flux leakage fields, thus forming a visible indication that the inspector can detect.

Advantages and Disadvantages

The primary advantages and disadvantages when compared to other NDT methods are:

Advantages-

·         High sensitivity (small discontinuities can be detected).

·         Indications are produced directly on the surface of the part and constitute a visual representation of the flaw.

·         Minimal surface preparation (no need for paint removal)

·         Portable (materials are available in aerosol spray cans)

·         Low cost (materials and associated equipment are relatively inexpensive)

Disadvantages-

·         Only surface and near surface defects can be detected.

·         Only applicable to ferromagnetic materials.

·         Relatively small area can be inspected at a time.

·         Only materials with a relatively nonporous surface can be inspected.

·         The inspector must have direct access to the surface being inspected.

Magnetic particle inspection is a process used in almost all heavy manufacturing industries like, graphite, iron and steel, automobiles, energy, defense and transportation. It is an important non-destructive testing method used in the manufacturing sector of heavy industries, during final inspection, process inspection, quality control, receiving inspection, maintenance and overhaul. The NDT training institute in Hyderabad and NDT institutes in Vishakhapatnam offer this valuable course for endless job opportunities in the engineering sector all over the world.