Non Destructive Examination (NDE)
Dye or liquid penetrant inspection
is a widely applied to locate
surface-breaking defects in all non-porous materials (metals,
plastics, or ceramics). The inspection is a two-stage process.
Firstly the penetrant is applied to the surface. The penetrant is
designed to fill any defects that exist on the surface. After some
time to allow the penetrant to fully infiltrate any defects, a
developer is used to highlight high concentrations of the penetrant.
Penetrant may be applied to both non-ferrous
and ferrous (magnetic) materials, but for inspection of ferrous components magnetic
particle inspection is preferred for its sub-surface detection
capability. DPI is used to detect casting and forging defects,
cracks, and leaks in new products, and fatigue cracks on in-service