Small cracks and other defects in metal components aren’t always visible to the naked eye. This is especially true when the metal components are covered in layers of paint or protective coatings.
Paint and protective coatings can’t “fix” a structural crack or prevent it from worsening. In fact, under layers of paint or coatings, hidden flaws can flex, grow and even trap moisture. Eventually, these flaws may compromise the performance, safety and structural integrity of the metal component or part.
Eddy current testing is one method of non-destructive testing (NDT) that allows technicians to detect surface and near-surface defects in electrically conductive materials without damaging the component. In many cases, eddy current testing can be performed through non-conductive paint, primers or protective finishes.
How Does Eddy Current Testing Work?
Eddy current testing uses electromagnetic induction to evaluate the condition of electrically conductive materials such as aluminum and steel.
During an eddy current inspection, a trained technician places a specialized probe near the surface of a metal component. The probe uses a conductor with an alternating current to create a magnetic field around the object being tested. This generates tiny electrical currents, known as eddy currents, within the material.
When eddy currents encounter a crack, defect or change in material properties, their flow is disrupted. Specialized testing equipment detects these disruptions, allowing technicians to identify issues such as:
- Cracks
- Surface wear from erosion
- Corrosion
- Wall or thickness loss
- Pitting
Using advanced analysis software, our experienced inspectors can pinpoint flaws and provide the data customers need to make informed decisions without damaging materials.
Can Eddy Current Testing Find Cracks Under Paint or Coatings?
Some non-destructive inspection methods require direct access to the bare metal surface, meaning the component or part must be stripped and prepped before testing.
One of the top advantages of eddy current testing is its sensitivity. Eddy current testing can detect cracks hidden beneath non-conductive paint and protective coatings. This makes it especially useful for inspecting pre-painted or coated components where removing the protective finish would be too costly or time-consuming.
While not every application is ideal for eddy current inspection, it’s an efficient solution for manufacturing quality control, research and development, and inspections of components already in service.
Benefits of Eddy Current Non-Destructive Testing
Beyond detecting cracks beneath paint, eddy current testing can also accurately measure material and coating thickness without damaging the part.
This makes eddy current non-destructive testing an excellent solution for research and development, manufacturing quality control and in-service inspections.
Schedule Eddy Current Testing at American Testing Services
When you need to verify the safety and reliability of in-service components or parts with paint or coatings, look no further than American Testing Services.
Our experienced inspectors deliver reliable eddy current testing data ranging from basic thickness measurements and material conductivity evaluations to complex analyses of aerospace-grade engineering materials.
Get in touch with us today and let us help you find the right non-destructive inspection solution for your specific application.