7.5 Manufacturing Applications

Manufactured parts represent a wide category of applications with varying materials and geometries. The applicability of ultrasonic flaw detection is dependent on the specific part geometry and material, and the type of flaws that are likely to occur, so potential applications must be evaluated on an individual basis. However in many cases, ultrasonic flaw detection can provide a reliable method of characterization. Common examples include:

• Manufacturing welds -– This is a broad category consisting of manufactured assemblies made by joining two or more metal parts. Laser welds and similar techniques used to join sections of metal can frequently be tested, although geometry must be favorable. Consult Olympus NDT for details.
• Friction welds -– This is a category of welds in which metal or plastic parts are joined through a process where heat is generated by mechanical friction as surfaces are pressed together. In many cases friction welds are ultrasonically inspectable. The inspector needs to consider relative acoustic impedances of the materials being joined as well as the the specific joint geometry.
• Gear welds -– Small angle beams or radiused delay line transducers can often be used to verify depth of penetration in laser welds joining the outer ring and inner hub of large gear assemblies.
• Babbitt bearings -– Bonding between Babbitt metal liners and bearing shells can be tested with radiused delay line transducers. Voids in the cast Babbitt can also be located.
• Thermal fusion joints in plastic parts -– Fusion in plastic assemblies can usually be tested with small straight beam transducers as long as the fusion plane is parallel to the outside surface.

Fiberglass and Composites