Quantitative Evaluation of One-Dimensional Temperature Distribution on Material Surface Using Surface Acoustic Wave

Abstract

A quantitative method for measuring a one-dimensional temperature distribution on a material surface using a surface acoustic wave (SAW) is presented. The principle of the method is based on the temperature dependence of the velocity of the SAW propagating on a material surface. An effective method consisting of a SAW velocity measurement and an inverse analysis coupled with a one-dimensional finite difference calculation is developed to determine the surface temperature distribution quantitatively. To demonstrate the practical feasibility of the method, surface temperature distributions for aluminum and steel plates are examined. The SAW of each plate during heating is measured using a laser interferometer based on photorefractive two-wave mixing. The surface temperature distributions determined by the ultrasonic method almost agree with those measured using an infrared camera.

New ultrasonic thermometry and its applications to temperature profiling of heated materials

“…Bulk wave such as a longitudinal or shear wave is used for profiling internal temperatures and surface wave is used for surface temperature. The procedure for determining surface temperature distributions by SAW is described in [13].…”

“…It should be noted in the works that the internal temperature distribution can be successfully determined from the transit time of a longitudinal wave (LW) propagating through the thick plate. Since the surface wave velocity (SAW) propagating on a material surface also exhibits temperature dependence [11] [12], the ultrasonic inverse method is also effective in surface temperature measurements [13] while SAW measurements on the surface of heated material are performed. One of the advantages of using the SAW is that it can be applied to any material with a shiny or mirror-finished surface to which the infrared radiation technique cannot be applied.…”

Two-dimensional monitoring of surface temperature distribution of a heated material by laser-ultrasound scanning

“…Recently, the ultrasonic inverse method mentioned above has been modified to be adapted to surface temperature determination by SAW [9]. In the modified method, one-dimensional unsteady heat conduction with a constant thermal diffusivity is considered for the surface of a flat plate whose single side is uniformly heated.…”

“…The advantage of using the method is that no information on the thermal boundary condition at the heating side is needed for inversion. It was demonstrated through an experiment with a heated plate that the method with SAW is useful for measuring surface temperature distribution in a certain direction [9]. In this work, the method has been applied to two-dimensional mapping of surface temperature distribution.…”

“…The advantage of the method is that no information on the thermal boundary condition at the heating surface is needed for inversion. Recently, the ultrasonic method is modified to be adapted to surface temperature determination by surface acoustic wave (SAW) [9].…”