The Liquid Penetrant Method is used to detect
discontinuities which are open to the surface of the material
being examined. This method may be used on both ferrous and nonferrous
materials. Liquid Penetrant examination may be used for the detection of
surface discontinuities such as cracks, seams, laps, cold shuts, laminations
and porosity. We can provide both visible and fluorescent Liquid Penetrant
Examination Services.
Scientific
Principles
Penetrant solution is applied to the surface of
a clean component. The liquid is pulled into surface-breaking defects by
capillary action. Excess penetrant material is carefully cleaned from the
surface. A developer is applied to pull the trapped penetrant back to the
surface where it is spread out and forms an indication. The indication is much
easier to see than the actual defect.
Main Uses
Used to locate cracks, porosity, and other
defects that break the surface of a material and have enough volume to trap and
hold the penetrant material. Liquid penetrant testing is used to inspect large
areas very efficiently and will work on most non-porous materials.
Main
Advantages
- large
surface areas or large volumes of parts/materials can be inspected rapidly and
at low cost;
- parts
with complex geometry are routinely inspected;
- indications
are produced directly on surface of the part providing a visual image of the
discontinuity;
- equipment
investment is minimal.
Disadvantages
- detects
only surface flaws;
- surface
preparation is critical as contaminants can mask defects, surface breaking
defects;
- requires
a relatively smooth and nonporous surface;
- post
cleaning is necessary to remove chemicals;
- requires
multiple operations under controlled conditions;
- chemical
handling precautions are necessary (toxicity, fire, waste).
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here if
you require any more information or a quote.