Novel applications of NDT to the monitoring of manufacturing processes

This paper discusses opportunities for the application of NDT techniques to the monitoring of manufacturing processes, including off-line quality control, on-line monitoring and close-loop process control. Examples are given of the application of ultrasonics to in-situ weld monitoring and to high temperature process measurements in the steel industry, and of the application of acoustic monitoring to process such as machining, drawing, extrusion, mixing and particle sizing. Magnetic techniques are discussed in the context of measuring stress and case depth in manufactured components, and positron annihilation for the determination of the degree of plastic deformation during material fabrication.