Ultrasonic characterization of the interfacial zone in a copper/aluminum explosive weld

An ultrasonic method was developed to test the amplitude of interfacial oscillations in a copper/aluminum explosive weld; this characterization Of the interfacial topography can then be used to infer the weld condition. The new test scheme was applied to several copper/aluminum specimens and the ultrasonic signals were analyzed based on a simple cosine model of the interfacial profile. The results obtained from the ultrasonic tests were found to be consistent with those obtained from scanning electron microscope analysis. Cracked intermetallic particles at the weld interface of some of the samples were identified using both scanning electron microscope and energy dispersive X-ray techniques; the extent of such compounds can be correlated to the presence of turbulent "waves" in the weld topography.