Discussion forthe Semiinfinite Medium Approximation and the Thermal Diffusion Velocity in Laser Heat Treatment

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Discussion for the Semi infinite Medium Approximation and the Thermal Diffusion Velocity in Laser Heat Treatment

It is a conventional method to regard laser-iradiated object as a semi-infinite medium with invariable thermal physical property parameters for approximate analyses of thermal acting of laser heat treatment. So far, 2 and have been taken as the thermal diffusion distance and the thermal diffusion velocity respectively, at the time t after heat fluctuation in materials with a thermal diffusion coefficient α, and as a result, the feasibility of the approximately estimating method about semi-infinite medium is judged. This paper indicates that, due to quantitative investigation of heat energy diffusion, the thermal diffusion distance of 3 and the thermal diffusion velocity of 1.5 can more accurately describe the physical process of heat conduction. Finally, an applied example of approximately estimating the temperature field of laser heat treatment is presented.