Which nondestructive testing method uses magnetic particles to reveal flux leakage around discontinuities?

Which nondestructive testing method uses magnetic particles to reveal flux leakage around discontinuities?

• A. Magnetic Particle Inspection
• B. Dye Penetrant Inspection
• C. Ultrasonic Testing
• D. Radiography

Answer: (A)

Magnetic Particle Inspection uses magnetization of a ferromagnetic material and finely divided magnetic particles to reveal flux leakage around defects. When a magnetic field is applied, discontinuities such as cracks or inclusions disturb the field and create leakage near the surface. The magnetic particles gather at these leakage fields, forming visible indications that outline the flaw. This method is ideal for locating surface and near-surface defects in ferromagnetic metals, using either dry powder or a wet suspension. In contrast, dye penetrant detects surface-breaking flaws by capillary action of dye on the surface, ultrasonic testing uses high-frequency sound waves to find internal features, and radiography relies on penetrating radiation to image internal structure.

Magnetic Particle Inspection uses magnetization of a ferromagnetic material and finely divided magnetic particles to reveal flux leakage around defects. When a magnetic field is applied, discontinuities such as cracks or inclusions disturb the field and create leakage near the surface. The magnetic particles gather at these leakage fields, forming visible indications that outline the flaw. This method is ideal for locating surface and near-surface defects in ferromagnetic metals, using either dry powder or a wet suspension. In contrast, dye penetrant detects surface-breaking flaws by capillary action of dye on the surface, ultrasonic testing uses high-frequency sound waves to find internal features, and radiography relies on penetrating radiation to image internal structure.