Client: Automotive Safety Systems Manufacturer

Technology: Acoustic Resonance Testing AT


The client part was an investment casting used in an automotive engine application. Due to process variations inherent to the casting process, the potential for several defects exists. Parts can have unacceptable nodularity, porosity, dimensional or density variation, cold shuts or other flaws. It is common for large casting suppliers to employ several types of non-destructive testing and inspection, often done in series, to contain defective parts. Despite these inspections, flawed parts sometimes escape, leading to customer complaints and major financial penalties.


AMS developed an Acoustic Resonance Inspection process, which was implemented following the client’s own internal radiographic and magnetic particle inspections. Parts that were accepted by the client’s inspection were then passed onto AMS for Acoustic Inspection. AMS’s Acoustic Resonance Inspection process always tests the entire part to detect multiple types of defects, often not detected by a client’s in-house inspections.

Client Benefits

  • Potential defects, which were accepted by the client’s in-house inspections, were detected by AMS’s inspection and were then contained.
  • Demanding end user automotive safety systems requirements were met, and the client’s supplier PPM score was reduced.
  • The AMS ARI reject rate highlighted the benefit of an additional layer of inspection beyond the client’s in-house processes.