An acoustic emission (AR) monitoring technique has been developed to detect embrittled brazed joints. The technique involves the application of a slowly increasing proof load, during which time the specimen is monitored for AR activity emanating from the braze. The so-called Cantilever bend test (CHI) was originally developed by Drouillard [1] at the Rocky Flats Plant, Colorado, USA and was subsequently adopted within the AWE (Atomic Weapons Establishment) manufacturing process in the early 1980s, despite slight but subtle variations in the brazing processes. Over time, we find a steady increase in downtime because of the failure of the now obsolete, analogue AE instrumentation. This resulted in a development programme to Identify suitable replacement instrumentation, that could also be used to conduct an independent study of the brazing process, which until now had relied entirely on US data. In addition, it provided an opportunity to develop an 'intelligent' motor controller, to take over the role of the operator who until now, was required to control the entire tat sequence manually. This paper presents a summary of the research programme and presents typical results demonstrating the effectiveness of this monitoring technique.
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