Langley Alloys: Adding value with non-destructive testing

Aside from the distribution of high-performance metals, Langley Alloys can provide a wide range of additional services from our in-house capability. These include non-destructive testing, to confirm the integrity of the metal items before further processing.

Langley Alloys can offer both dye penetrant inspection (‘dye pen’) and ultrasonic testing (UT) by our team of experienced operators. Although usually applied to castings or forged shapes, where there is perhaps a greater risk of defect, it can still be selected by clients for rolled and forged bar if the application demands it.

Dye pen inspection is a relatively low-cost method to check for surface defects in a variety of components. ‘Dye pen’ inspection exploits capillary action, whereby a liquid is drawn in to small breaks or cracks that may exist in the surface. Firstly, the dye is applied to the clean surface of the item, by brush, spray or immersion.

It is allowed to sit for a period of time, typically up to 30 minutes, before excess dye is removed. A second solution, called the developer, is then applied in our case by aerosol spray. Again, it is left to ‘develop’ as it absorbs the liquid dye that has been held in any surface breaks and thereby highlights their location and approximate size. Visual inspection is carried out in a well-lit space usually, although UV light may be used for certain dyes to increase the resolution.

Ultrasonic testing (UT) is undertaken by Langley Alloys with our team of qualified operators. It uses ultrasonic waves, which are of higher frequency than the human ear can recognise, to identify internal features and defects inside the volume of various metal components. Any such features disrupt the reflection of the wave as it attempts to pass through the item, and so will show up on the inspection meter as a different signal or ‘noise’. The size of the reading can relate to both the size and location of the internal feature.

By undertaking testing in-house, Langley Alloys can save our customers both time and cost. We are used to working to demanding standards, including BAe Systems, the US Navy and BNFL, with our team of operators qualified to ASNT Level II standards for UT. Other options include PMI and radiation testing, hardness and tensile testing, heat treatment plus first-stage machining.

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