Hand held Eddy Current Tester for Accurate Depth Measurement of Case Hardening in Aerospace Materials

New technology is needed for nondestructive inspection (NDI) of the interface depth on case hardened aerospace components such as gears and drive trains. At this time, the standard method of measurement is destructive and sample dependent - cross sectioning and traverse-hardness testing. An NDI technology capable of measuring the core-to-case interface depth on small, geometrically complex areas to high accuracy would be ideal. Existing NDI technologies such as coil eddy current testing are still in the laboratory stage, and are limited to measuring large, homogeneous samples because of the size of coils required for sensitivity. RMD proposes a revolutionary new eddy current technology it has recently patented based on using a microscopic, high sensitivity, solid state AMR sensing element to measure the case hardening interface depth. The 2-D solid-state sensor will allow miniaturizing of the ECT probe so that it can be used on small geometries with accurate results. The proposed NDI system will be portable, versatile, and simple to operate. Through making possible 100% testing of components during fabrication as well as in-the-field testing, the proposed NDI technology will improve aircraft integrity and crew safety, improve readiness, and reduce the cost and complexity of inspections.