Material Condition Assessment With Eddy Current Sensors

Author:  Goldfine, Washabaugh, Sheiretov, Schlicker, Lyons,
Source:  US Patent 2006/0244443A1
Doc ID:  2006045
Year of Publication:  2006
Abstract:  
ABSTRACT Eddy current sensors and sensor arrays are used for process quality and material condition assessment of conducting materials. In an embodiment, changes in spatially registered high resolution images taken before and after cold work processing reflect the quality of the process, such as intensity and coverage. These images also permit the suppression or removal of local outlier variations. Anisotropy in a material property, such as magnetic permeability or electrical conductivity, can be intentionally introduced and used to assess material condition resulting from an operation, such as a cold work or heat treatment. The anisotropy is determined by sensors that provide directional property measurements. The sensor directionality arises from constructs that use a linear conducting drive segment to impose the magnetic field in a test material. Maintaining the orientation of this drive segment, and associated sense elements, relative to a material edge provides enhnaced sensitivity for crack detection at edges.