Nondestructive testing methods are those which don't modify the materials during the testing, so they can be used to test 100% of end products.
There are different types of NDT methods such as:
- Eddy current (mainly for surface quality and physical properties)
- Vision (when the surface can be accesed by humans or cameras)
- Ultrasonics
- X-Ray
- Magnetic particles
- Penetrant liquids
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Eddy current
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Vision
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Ultrasonic testing
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Penetrant liquids
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Magnetic particles
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X-ray
- Use
- Surface and subsurface discontinuities
- Changes in hardness or conductivity near the surface
- 100% of the production need to be tested
- Materials can't be directly accessed by people
- Advantages
- Recognized method for most of the standards and codes
- Repetitiveness
- Sensitiveness
- Reliability
- Can be easyly adopted
- Low cost
- Doesn't need human extensive participation
It's the best method for surface testing
- Use
- Surface discontinuities
- Materials can be accessed by people or by cameras
- Advantages
- Intuitiveness (easy to understand the results)
- Can be easyly adopted
However it's very dependent on environmental conditions such us surface conditions, light and floating particles
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- Advantages
- Recognized method for most of the standards and codes
- Repetitiveness
- Can be easyly adopted
However it's an expensive method and it has an extensive couplant consumption
- Use
- Surface discontinuities
- Materials can be directly accessed by people
- Only statistics samples are necessary to be tested
However it's a dirty method and needs human execution
- Use
- Surface discontinuities
- Materials can be directly accessed by people
- Only statistics samples are necessary to be tested
However it's a dirty method and needs human execution
- Use
- Internal discontinuities
- Materials surfase can be directly accessed by people
- Discrete production
- Advantages
- Intuitiveness
- Reliability
- Accuracy
However it's a dangerous and very expensive method
