What are the methods of magnetic particle inspection?
In magnetic particle inspection, circular magnetization is used to detect lengthwise cracks. passed through the part or through an electrical conductor within the part. The circular magnetic field cutting across the crack attracts and holds iron powder, to indicate the invisible defects.
What method of magnetic particle inspection is used most often?
Aircraft Maintenance NDT Principles
| Question | Answer |
|---|---|
| A part which is being prepared for dye penetrant inspection should be cleaned with… | A volatile petroleum base solvent |
| What method of magnetic particle inspection is used most often to inspect aircraft parts for invisible cracks and other defects? | Continuous |
How MPI is used to inspect the crack?
Magnetic particle inspection is a simple NDI method used to detect cracks at the surface of ferromagnetic materials such as steels and nickel-based alloys. The inspection process begins with the magnetisation of the component. The magnetic particles are attracted to the flux leakage and thereby cluster at the crack.
What is the basic principle of magnetic particle testing?
The principle of the method is that the specimen is magnetised to produce magnetic lines of force, or flux, in the material. If these lines of force meet a discontinuity, such as a crack, secondary magnetic poles are created at the faces of the crack.
Why use of DC is better than AC in the magnetic particle inspection?
DC gives the most penetration and is recommended if subsurface discontinuities need to be detected. AC is recommended if the surface is rough, because AC gives the particles more mobility than DC.
What are the limitations of magnetic particle inspection method?
Disadvantages of the Magnetic Particle method of Non-Destructive Examination are: It is restricted to ferromagnetic materials – usually iron and steel, and cannot be used on austenitic stainless steel. It is messy. Most methods need a supply of electricity.
What is magnetic particle inspection used for?
Magnetic Particle Inspection (MPI) is a non-destructive testing method that can detect surface and subsurface flaws in ferromagnetic materials. Magnetic particle inspection is often carried out to help determine an item’s fitness for use or conformity.
Is standard for magnetic particle inspection?
Magnetic particle users outside the aerospace industry have typically used ASTM E709 Standard Guide for Magnetic Particle Testing as their baseline standard for procedures. That’s why there are also Standard Practices like ASTM E1444 Standard Practice for Magnetic Particle Testing.
What is another name for magnetic particle inspection?
Magnetic Particle Testing (MPT), also referred to as Magnetic Particle Inspection, is a nondestructive examination (NDE) technique used to detect surface and slightly subsurface flaws in most ferromagnetic materials such as iron, nickel, and cobalt, and some of their alloys.
Where is magnetic particle testing used?
This method is used for the detection of surface and near-surface flaws in ferromagnetic materials and is primarily used for crack detection. The specimen is magnetised either locally or overall, and if the material is sound the magnetic flux is predominantly inside the material.
What is the advantage of using direct current is magnetic particle inspection?
The often quoted advantage of the use of D.C. magnetising is its ability to detect sub- surface defects.
What are the advantages of magnetic particle inspection?
Advantages of the Magnetic Particle method of Non-Destructive Examination are:
- It is quick and relatively uncomplicated.
- It gives immediate indications of defects.
- It shows surface and near surface defects, and these are the most serious ones as they concentrate stresses.
- The method can be adapted for site or workshop use.