Current methodology for testing the degree of sensitization (DoS) in 5XXX aluminum alloys is destructive and not practical for inspecting boats and material in service. A nondestructive inspection (NDI) method is required as a single fieldable probe for this and associated requirements. Proto evaluated a combination of x-ray diffraction (XRD), ultra-sonics and eddy current technologies and concluded that such a probe would be unnecessarily too complex. Proto found that XRD alone offers the highest potential to solve this difficult problem. The Team has measured several AA5083 specimens confirming our premise that distinctive XRD phase shifts are detectable and measureable for various tempersa strong indicator of technical feasibility. The Proto Team proposes to conduct a thorough test and analysis program of AA5383 in three tempers, coincident with the quantitative measurement of numerous XRD parameters and the application of several analytic and correlation methods. The Team will demonstrate the feasibility of XRD on AA 5383 alloy to meet the stated requirements and define a realistic plan for Phase II system development and demonstration. Proto develops portable nondestructive XRD systems tailored to customer requirements and proposes to deliver an effective NDI system for measuring DoS onboard ships, in shipyards and factories.
Benefit: The Proto Team believes that x-ray diffraction (XRD) affords realistic promise to quantitatively characterize the degree of sensitization (DoS) in 5XXX aluminum alloys at or near the surface and to correlate directly with ASTM G67 results. Moreover, XRD is nondestructive and provides useful critical information about the state of the material and welds; whereas, neither ASTM B928 nor the G67 Nitric Acid Mass Loss Test (NAMLT) can meet these needs. XRD is well known for its reliability in measuring residual stress and determining structural integrity thus providing a sound basis for health monitoring DoS over a system life-cycle. Proto envisions a man-portable, rugged and fast XRD scanning system with a single probe that can quantitatively measure the DoS in laboratory and operational environments. Proto expects its production model NDI XRD system will initially complement current ASTM tests and eventually replace some current testing, especially for in-service ships and material, with attendant cost savings. This NDI capability for DoS in 5XXX is expected to gain widespread support of: (a) US Navy researchers and shipyards, (b) Aluminum producers for in-process quality control, (c) Incoming quality inspection functions and (d) Commercial shipyards both domestic and foreign.
Keywords: residual stress (RS), residual stress (RS), Nondestructive inspection (NDI), welds, DoS, Nondestructive Evaluation (NDE), xrd parameters, x-ray diffraction (xrd)
