Thermal Science 2015 Volume 19, Issue 5, Pages: 1845-1854
https://doi.org/10.2298/TSCI150307080T
Full text ( 325 KB)
Cited by
Application of pulsed flash thermography method for specific defect estimation in aluminum
Tomić Ljubiša D. (Technical Testing Centre, Belgrade)
Jovanović Dalibor B. (Technical Testing Centre, Belgrade)
Karkalić Radovan M. (University of Defense, Military Academy, Belgrade)
Damnjanović Vesna M. (Faculty of Mining and Geology, Belgrade)
Kovačević Branko V. (CBRN Defense Centre, Kruševac)
Filipović Dalibor D. (Serbian Armed Forces, Niš, Serbia)
Radaković Sonja S. (Medical Faculty of the Military Medical Academy, University of Defense, Belgrade, Serbia)
Nondestructive thermal examination can uncover the presence of defects via
temperature distribution profile anomalies that are created on the surface as
a result of a defect. There are many factors that affect the temperature
distribution map of the surface being tested by Infrared Thermography.
Internal defect properties such as thermal conductivity, heat capacity and
defect depth, play an important role in the temperature behavior of the
pixels or regions being analyzed. Also, it is well known that other external
factors such as the convection heat transfer, variations on the surface
emissivity and ambient radiation reflectivity can affect the thermographic
signal received by the infrared camera. In this paper we considered a simple
structure in the form of flat plate covered with several defects, whose
surface we heated with a uniform heat flux impulse. We conducted a
theoretical analysis and experimental test of the method for case of defects
on an aluminum surface. First, experiments were conducted on surfaces with
intentionally created defects in order to determine conditions and boundaries
for application of the method. Experimental testing of the pulsed flash
thermography (PFT) method was performed on simulated defects on an aluminum
test plate filled with air and organic compound n-hexadecane, hydrocarbon
that belongs to the Phase Change Materials (PCMs). Study results indicate
that it is possible, using the PFT method, to detect the type of material
inside defect holes, whose presence disturbs the homogeneous structure of
aluminum.
Keywords: infrared thermography, nondestructive testing, pulsed flash thermography, defect estimation, phase change material