Measurement of thermal diffusivity of isotropic materials using a laser flash method and its validation by finite element analysis

Two experimental arrangements have been used to measure the thermal diffusi vity at room temperature using laser pulse healing. One uses circular disc specimens and the other rectangular plate-like specimens to measure both on e-dimensional and three-dimensional heat transfer. In both experimental con figurations a pulsed laser beam which has a circular cross section is irrad iated onto the front surface of the specimen. The time dependence of the te mperature response of a circular area on the back surface of the specimen i s measured using a radiation detector. The experimental data is then used t o calculate thermal diffusivity using appropriate analytical expressions. T he theory of these methods is outlined and results are discussed. In additi on, finite element models have been generated for one-dimensional and two-d imensional transient thermal analysis of the specimens. These results are s hown to be in close agreement with the results of experiments within the bo unds of experimental error, hence, validating the experimental measurements .