Magnetic Particle Inspection MPI or Magnetic Particle Testing MT is the method for finding Linear Defects in Ferro Magnetic Materials by utilization of Magnetic Field.
Only ferromagnetic materials can be inspected using MPI test. The materials with major content as Ferrous or Cobalt or Nickel is called as ferromagnetic material.
Magnetic Particle Inspection utilizes wide range of machines such as :
- Yoke
- Prod
- Head Shot Machine
- Central Conductor
- Rigid Coils
- Wire Wrap
The MPI test method is used to find the Surface and Sub Surface defects only. MPI testings does not detects internal defects.
To find internal defects Magnetic Particle Inspection(MPI) testing is followed by internal defect detection method such as Ultrasonic testing or Radiographic testing method.
FAQ: How much deep does MPI testing finds defects ?
Magnetic Particle Testing Method detects surface and sub surface defects upto 8mm approximately. To find deeper defects a high current (high Amps) should be used in order to produce deeper and stronger magnetic field.
- AC current for a electromagnetic Coil finds out Surface defects
- DC current for a electromagnetic coil finds out Sub Surface defects
MPI testing method can be done as Visible and Fluorescent method
FAQ: Which is best, Fluorescent or Visible MPI ?
Ans: Fluorescent MPI is more sensitive than Visible method.
For Training and certification on Non destructive testing methods and Third party inspection for Magnetic Particle testing services and other nondestructive testing services visit https://aqcinspection.com/non-destructive-testing/.
Find our Blog updates at https://ndtcenter.blogspot.com/