Study on Three-Dimensional Temperature Field Induced by Laser Irradiation with Different Intensity Distribution

In this paper, a three-dimensional temperature field simulation model of metal surface irradiated by laser is established to analyze the temperature field distribution of Q235 metal plate irradiated by laser beam. The difference of temperature history and temperature field between Gauss fundamental mode beam and uniform rectangular beam is compared. The results show that the rectangular beam can make the temperature field more uniform, which is more suitable for laserassisted heat treatment and lamination process. Introduction As a new processing method, laser processing technology is widely used in materials, machinery and other industries, involving advanced processing technologies such as laser remanufacturing[1], cutting[2] and quenching[3]. In laser-assisted thermal processing, laser is used as a heat source to irradiate the surface of materials with extremely high power density, which makes the temperature of materials rise rapidly to meet the technological requirements. Subsequently, the material exits the irradiation zone and enters the cooling stage. The heating rate, the maximum temperature and the duration of the processing temperature are the main processing parameters. The temperature field has a great influence on the properties of materials[4]. When laser irradiates materials, the energy flow is complex. Using thermal infrared camera to measure temperature field directly is easy to be disturbed. And when using thermal resistance to measure the internal temperature of materials, the placement of thermal resistance will affect the internal structure of materials, which will also produce errors. Therefore, it will be very difficult to study the temperature field by experimental methods[5]. Most scholars use numerical or simulation methods to study the temperature field of laser irradiation. Wang G[6] established a two-dimensional temperature field model of laser irradiated materials by numerical method. Kashani[7] used Green's function to obtain the analytical solution of the transient temperature field in a rotating cylinder subjected to local laser heat source. Wang Y[8] proposed a numerical simulation method for studying the temperature field of laser quenching process. In summary, the research on temperature field of laser irradiation is mainly focused on two-dimensional simulation, ignoring the temperature field distribution in X or Y asix. And there is little research on the influence of different beam distribution on the time-dependent temperature field history. In this paper, the three-dimensional temperature field of laser irradiation is studied by simulation model. The temperature history and temperature field distribution of the material are analyzed, and the spatio-temporal distribution differences of temperature field irradiated by Gauss fundamental mode beam and uniform rectangular heat source are discussed. Mathematical Model of Temperature Field When metal plate is irradiated by a vertical laser beam, most of the light energy is absorbed and converted into heat energy. As the laser beam moves, heat is continuously transmitted, as shown in Fig. 1. Therefore, according to the first law of thermodynamics, a three-dimensional heat transfer model is established. The equation of transient temperature field is as follows: International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019) Copyright © 2019, the Authors. Published by Atlantis Press. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). Advances in Intelligent Systems Research, volume 168