Liquid or Dye Penetrant Testing
Dye penetrant testing is a non–destructive method for finding discontinuities that are open to the surface of solid and essentially non-porous materials. Indications of flaws can be found regardless of the configuration, internal structure, or chemical composition of work piece being tested and regardless of flaw orientation. Liquid penetrant can seep into (and be drawn into) various types of minute surface openings by capillary action. Because of this, the process is well suited for the detection of all types of surface cracks, laps, porosity, shrinkage areas, laminations and similar discontinuities in castings, forgings, welds and other product forms. Dye penetrant inspection is used extensively for the testing of wrought and cast products of ferrous and non-ferrous metals, powder metallurgy parts, ceramics and glass objects.