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→Non-Destructive Test Methods
Typically the non-destructive testing of braze joints requires more elaborate test equipment. Besides this such test methods have limitations regarding the shape of the contact tips and/or carriers. The prevalent methods are ultrasound testing and X-ray analysis.
*Ultrasonic testing <br />This method is based on the disruption of the propagation of sound waves in different media. High resolution modern test systems with graphic print-out capabilities and analytical software are capable to detect even small (<0.5 mm diameter) voids in the braze joint. The portion of the wetted areas is calculated as a percentage of the whole joint area. <xr id="fig:Ultrasound print-out of braze joints"/> (Fig. 3.15 ) shows an example of different braze qualities for a Ag/SnO<sub>2</sub> contact tip brazed to a copper carrier and illustrates the position and size of void areas as well as the final joint quality.<br /><figure id="fig:Ultrasound print-out of braze joints">
[[File:Ultrasound print-out of braze joints.jpg|right|thumb|Ultrasound print-out of braze joints between Ag/SnO 88/12 tips and Cu carrier with 2
different degree of wetting (dark areas = voids)]]
*X-Ray testing <br />X-ray testing is an additional method for evaluating brazed joints. Using finefocus X-ray beams it is possible to achieve a sufficient picture resolution. There are however limitations about the thickness of the contact tip compared to the size of the void area. This expensive test method is rarely used for contact assemblies.<br />
