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Noncontacting Thermoelectric Detection of Material Imperfection in Metals. (Final Report, September 15, 2000-March 15, 2005).

DE2006840905

Publication Date	2005
Personal Author	Nagy, P. B.; Nayfeh, A. H.; Faidi, W. I.; Carreon, H.; Lakshminaraya, B.
Page Count	94
Abstract	This project was aimed at developing a new noncontacting thermoelectric method for nondestructive detection of material imperfections in metals. The method is based on magnetic sensing of local thermoelectric currents around imperfections when a temperature gradient is established throughout a conducting specimen by external heating and cooling. The surrounding intact material serves as the reference electrode therefore the detection sensitivity could be very high if a sufficiently sensitive magnetometer is used in the measurements. This self-referencing, noncontacting, nondestructive inspection technique offers the following distinct advantages over conventional methods: high sensitivity to subtle variations in material properties, unique insensitivity to the size, shape, and other geometrical features of the specimen, noncontacting nature with a substantial stand-off distance, and the ability to probe relatively deep into the material. The potential applications of this method cover a very wide range from detection metallic inclusions and segregations, inhomogeneities, and tight cracks to characterization of hardening, embrittlement, fatigue, texture, and residual stresses.
Keywords	Metals Nondestructive testing Defects(Materials) Thermoelectricity Magnetometers Electrodes Temperature gradients Heating Cooling Standoff Cracks Residual stress Fatigue(Mechanics) Nagnetic detectors Hardening High sensitivity Embrittlement
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Cincinnati Univ., OH. Dept. of Aerospace Engineering and Engineering Mechanics.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200616

Noncontacting Thermoelectric Detection of Material Imperfection in Metals. (Final Report, September 15, 2000-March 15, 2005).

Noncontacting Thermoelectric Detection of Material Imperfection in Metals. (Final Report, September 15, 2000-March 15, 2005).
DE2006840905

Publication Date	2005
Personal Author	Nagy, P. B.; Nayfeh, A. H.; Faidi, W. I.; Carreon, H.; Lakshminaraya, B.
Page Count	94
Abstract	This project was aimed at developing a new noncontacting thermoelectric method for nondestructive detection of material imperfections in metals. The method is based on magnetic sensing of local thermoelectric currents around imperfections when a temperature gradient is established throughout a conducting specimen by external heating and cooling. The surrounding intact material serves as the reference electrode therefore the detection sensitivity could be very high if a sufficiently sensitive magnetometer is used in the measurements. This self-referencing, noncontacting, nondestructive inspection technique offers the following distinct advantages over conventional methods: high sensitivity to subtle variations in material properties, unique insensitivity to the size, shape, and other geometrical features of the specimen, noncontacting nature with a substantial stand-off distance, and the ability to probe relatively deep into the material. The potential applications of this method cover a very wide range from detection metallic inclusions and segregations, inhomogeneities, and tight cracks to characterization of hardening, embrittlement, fatigue, texture, and residual stresses.
Keywords	Metals Nondestructive testing Defects(Materials) Thermoelectricity Magnetometers Electrodes Temperature gradients Heating Cooling Standoff Cracks Residual stress Fatigue(Mechanics) Nagnetic detectors Hardening High sensitivity Embrittlement
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Cincinnati Univ., OH. Dept. of Aerospace Engineering and Engineering Mechanics.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200616