IntermediateTopic 60 of 100Materials & Chemical
Non-destructive testing
Ultrasonic, radiographic, magnetic particle and dye penetrant inspection find flaws.
In depth
NDT finds flaws without damaging parts: visual, dye penetrant (surface cracks), magnetic particle (ferromagnetics), ultrasonic (internal flaws, thickness), radiography (X-ray, gamma), eddy current (conductive surfaces), thermography and acoustic emission. Choose by defect type and geometry; personnel certified.
Key points
- Probability of detection
- Phased-array UT
- Codes (ASME, ISO 9712)
ExampleWeld quality in pipelines is checked by radiography or ultrasonic testing.
What is Non-destructive testing?
Ultrasonic, radiographic, magnetic particle and dye penetrant inspection find flaws.
Why is it important to understand non-destructive testing?
Non-destructive testing finds flaws without damaging the part, which is essential for safety-critical welds, castings and aircraft.
What does ultrasonic testing do?
It sends high-frequency sound waves into a part and detects echoes from flaws, which gives the position and size of defects.
Which NDT method finds surface cracks in non-magnetic metals?
Dye penetrant testing, which draws a coloured dye into surface openings so that cracks become visible.
How is Non-destructive testing used in practice?
Typical applications include inspecting a weld for internal cracks with ultrasonic testing, checking a casting for surface cracks with dye penetrant and using radiography to see porosity inside a cast component.
What should I learn before Non-destructive testing?
Study "Failure analysis" first (topic 59 of 100 in Materials & Chemical). It covers the groundwork this topic builds on.
What are the key points of Non-destructive testing?
Probability of detection. Phased-array UT. Codes (ASME, ISO 9712).
Can you give an example of Non-destructive testing?
Weld quality in pipelines is checked by radiography or ultrasonic testing.
What comes after Non-destructive testing?
The next topic is "Material characterisation", which builds directly on this one.
How difficult is Non-destructive testing?
It is classed as Intermediate in Materials & Chemical (topic 60 of 100). It is an intermediate topic. Work through the beginner topics in Materials & Chemical first.