The great invention of the 20th century, non destructive testing (NDT), is an invaluable tool for the prevention and detection of materials damage or failure. Non destructive testing (NDT) is a subset of Non Destructive Evaluation (NDE), where the material is not altered by the testing process and can be used again. NDT is used for a variety of applications and materials, including metals, plastics and ceramics, as well as composites. This type of testing is widely used in aircraft and aerospace, as well as in industrial, automotive and medical fields.
There are various types of NDT, each with their own particular uses and benefits. One of the most common types is ultrasonic testing, which uses ultrasonic waves to identify flaws and defects within a material. Ultrasound is the most widely used NDT technique, as it is based on the properties of sound waves, which are easier to control and to adapt. Ultrasound is not only reliable and cost-effective, but also does not require any contact with the material; it is also possible to view the results of tests using digital images, rather than relying on visual or physical observation. Other types of NDT include radiography and chemical analysis, with each technique offering unique advantages and benefits.
For example, chemical analysis can be used to detect material degradation, especially in materials such as alloys, which are subject to chemical corrosion. Radiography is used to detect possible stress concentrations and fatigue fractures. Eddy current, thermography and acoustic emission testing can also be used for certain applications. NDT is increasingly used for structural inspections and for early detection of potential failures and wear. As the technology progresses, it is expected to become more widely used across a range of sectors.
When selecting NDT methods, engineers must consider the type of material being tested, the size of the part, the magnitude of the detail to be inspected and the environment in which it is being tested. The right choice of NDT method is essential, as each technique has benefits in certain conditions. It is also important to consider the cost of the tests, the accuracy of the results and the safety of personnel who will perform the tests.
NDT is becoming a more critical element in the prevention of failure, and is set to be an important part of the design and manufacturing process for many products. In addition, due to the variety of applications, NDT is also used for quality control purposes, to ensure accuracy and reliability of materials. Non destructive testing is here to stay, and it is certain to continue to revolutionise the way we go about detecting and preventing failure.
