Magnetic Particle Suspension Inspection
Magnetic particle suspension testing is a magnetic particle inspection where ferromagnetic particles are sprayed in a liquid carrier (oil-based or water-based). It improves detection sensitivity and allows precise detection of fine discontinuities.
Physico-chemical mechanism of action
Magnetic particle suspension testing uses ferromagnetic particles suspended in a liquid carrier (oil or water) that is sprayed on. These particles are moved by magnetic fields and gather at fine discontinuities in the material. The mobility of particles in the suspension increases their sensitivity for detecting microcracks or other defects.
Metallurgical relevance & welding risks
This test is especially important for quality control of welds. It can detect fine discontinuities that other methods cannot. However, inadequate spraying or a wrong choice of carrier can lead to inaccurate results and increase the risk of misdiagnosis.
Workshop practice & instructions
To perform magnetic particle suspension testing successfully, choose the correct carrier. Oil is suitable for high-temperature applications; water-based suspensions are better at lower temperatures. Particle size and concentration should follow manufacturer instructions. Adequate spraying of the test piece and proper application of the magnetic field ensure precise results.