Determination of the Type of Spatial Distribution of the Energy of a Thermal Source when a Laser Beam Acts on Steel

摘要

The action of a focused laser beam on metals at an intensity not exceeding the critical damage point results in heating and partial melting of the material thus affected. Light radiation is characterized by several controlling parameters, one of them being the distribution of radiation intensity within the hot spot. In the field of materials processing, the absorption coefficient for a given radiation wavelength, temperature-averaged over the metal surface, is of no less interest than the curve showing the time-averaged spatial distribution of radiation intensity. The average integral absorption coefficient for ShKh-15 steel within a temperature range not exceeding the boiling point was found to be 0.54. Maximum surface temperature is attained toward the end of the pulse action and reaches 2040C, thus exceeding the melting point of the steel but staying well below its boiling point. The accuracy of the method suggested by the author does not exceed 15--20%.