Thermal depth profiling of materials for defect detection using hot disk technique
Journal article, 2016

A novel application of the hot disk transient plane source technique is described. The new application yields the thermal conductivity of materials as a function of the thermal penetration depth which opens up opportunities in nondestructive testing of inhomogeneous materials. The system uses the hot disk sensor placed on the material surface to create a time varying temperature field. The thermal conductivity is then deduced from temperature evolution of the sensor, whereas the probing depth (the distance the heat front advanced away from the source) is related to the product of measurement time and thermal diffusivity. The presence of inhomogeneity in the structure is manifested in thermal conductivity versus probing depth plot. Such a plot for homogeneous materials provides fairly constant value. The deviation from the homogeneous curve caused by defects in the structure is used for inhomogeneity detection. The size and location of the defect in the structure determines the sensitivity and possibility of detection. In addition, a complementary finite element numerical simulation through COMSOL Multiphysics is employed to solve the heat transfer equation. Temperature field profile of a model material is obtained from these simulations. The average rise in temperature of the heat source is calculated and used to demonstrate the effect of the presence of inhomogeneity in the system.

finite element simulation

hot disk technique

thermal conductivity

inhomogeneous detection

Author

Besira Mekonnen Mihiretie

Chalmers, Physics, Condensed Matter Physics

Daniel Cederkrantz

Hot Disk AB

Maria Sundin

University of Gothenburg

Arne Rosen

University of Gothenburg

Henrik Otterberg

Hot Disk AB

Åsa Hinton

Ale Animal Clinic

Björn Berg

Ale Animal Clinic

Magnus Karlsteen

Chalmers, Physics, Condensed Matter Physics

AIP Advances

2158-3226 (ISSN)

Vol. 6 8 artikel nr 085217- 085217

Areas of Advance

Materials Science

Subject Categories

Condensed Matter Physics

DOI

10.1063/1.4961879

More information

Created

10/7/2017