Magnetic Particle Testing (MPT) is also known as Magnetic Particle Inspection (MPI). MPT / MPI is based on the principle of magnetism. Defects are identified as magnetic flux leakage occurs when there is a discontinuity in magnetized ferromagnetic material and fine iron particles sprinkled over specimens create cluster formation. MPT/MPI is the most widely used method as it is also known as the fastest method of NDT inspection.
Magnetic Particle Testing is used to identify surface and subsurface defects. Defects in depth are inspected till 0.6-inch depth only (Under ideal condition). To inspect surface defects we use AC current and for subsurface defects, we use DC current. Surface preparation is not as critical as in DPT and it is also known as the planer testing method.
Advantages of Magnetic Particle Testing-
· Magnetic Particle Testing technique is a very fast method.
· MPI requires a normal level of skill as its process is not very complicated.
· Specimens of big and small sizes can be tested quickly, whether they have a simple or complex shape.
· The immediate result is observed in MPI as it is quick and fast.
· Surface and sub-surface defects can easily be identified using the MPT method.
· MPI is portable for many parts and can be performed on-site or workstation.
· The cost of inspection using MPI is very low as compared to RT & UT.
Disadvantages of Magnetic Particle Testing-
· It cannot be used to inspect nonferromagnetic materials.
· Before inspection removal of paint is required in most of cases.
· In case painted parts get inspected, fumes may cause a fire.
· Electric supply is required in most of the cases for the magnetizing object.
Post cleaning & demagnetization is important.
NDT Level II Magnetic Particle Testing (MPT) Syllabus
· Principle of Magnetic Particle Testing
· Principle of Magnetic Particle Testing
· Type of Magnetizing Current
· Magnetic Particle Testing Equipment Review and Exercises
· Method of De-Magnetization
· Magnetic Particle Medium
· Magnetic Particle Testing Techniques Review and Exercises
· Magnetic Particle Testing Procedures
· Evaluation of Indications and Acceptance Standards
· Limitation Review and Exercises
After successful completion of training, participants will be appearing for the Level II exam.
Participants will be certified as NDT MPT Level II after successfully clearing the exam.