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

Nagy, P. B. ; Nayfeh, A. H. ; Faidi, W. I. ; Carreon, H. ; Lakshminaraya, B.

Technical Information Center Oak Ridge Tennessee

关键词: Metals;    Nondestructive testing;    Defects(Materials);    Thermoelectricity;    Magnetometers;   

RP-ID  :  DE2006840905

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

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.