What is the difference between non-destructive testing and destructive testing?
Non-Destructive Testing, or NDT, involves using non-intrusive evaluation methods on materials/components that are destined for service or are currently still in service. Various methods of NDT have been developed to analyze in-service components to determine if they may have been compromised at some point or have a manufacturing defect. NDT is used to look for indications of the onset of failure. Two types of NDT are magnetic particle inspection or ultrasonic testing. Both of these NDT techniques set up an electromagnetic field across the subject component. The EM waves are analyzed for breaks in continuity that might indicate the initiation of a crack or indicate an undesired inclusion within the material. Destructive testing, on the other hand, is generally performed when the component or material sample can no longer be used in service or is readily replaceable. Destructive testing includes measuring various mechanical or chemical properties such as Tensile Strength or Chemical Comp