空气与水中纳秒–毫秒组合脉冲激光辐照碳化硅效应模拟

Simulation of the Effect of Air and Water Nanosecond-Millisecond Pulsed Laser Irradiation on Silicon Carbide

摘要: 本研究利用COMSOL Multiphysics有限元软件，对纳秒–毫秒组合脉冲激光辐照碳化硅(SiC)的过程进行了数值模拟分析。通过构建二维轴对称几何模型，并设置相应的材料及激光参数，模拟了激光辐照碳化硅的物理过程，研究了单独的纳秒脉冲和毫秒脉冲以及它们组合的脉冲对碳化硅的影响。模拟结果表明，纳秒脉冲和毫秒脉冲的能量在时间上的叠加能够显著提高材料的中心点温度。当毫秒脉冲激光能量设为1000 mJ，纳秒脉冲激光能量设为15 mJ时，单独的脉冲能够使碳化硅的峰值温度接近其熔点(2700 K)。进一步分析了不同延迟时间条件下组合脉冲对碳化硅中心点温度的影响，发现在∆t = 2 ms时，中心点温度提升最大。此外，还考虑了水层对于激光辐照效果的影响，发现水层的存在对激光辐照过程的温升效果产生显著影响。本研究为理解和预测纳秒–毫秒组合脉冲激光辐照碳化硅的效果提供了理论依据，对于探索高性能碳化硅材料在极端条件下的应用有重要意义。

Abstract: This study utilizes the COMSOL Multiphysics finite element software to conduct a numerical simulation analysis of the process of irradiating silicon carbide (SiC) with a combination of nanosecond and millisecond pulse lasers. By constructing a two-dimensional axisymmetric geometric model and setting the corresponding material and laser parameters, the physical process of laser irradiation of silicon carbide was simulated. The study examined the effects of individual nanosecond pulses, millisecond pulses, and their combined pulses on silicon carbide. The simulation results indicate that the temporal superposition of nanosecond and millisecond pulse energies can significantly increase the central temperature of the material. When the millisecond pulse laser energy is set to 1000 mJ and the nanosecond pulse laser energy is set to 15 mJ, an individual pulse can bring the peak temperature of silicon carbide close to its melting point (2700 K). The study further analyzes the impact of combined pulses on the central temperature of silicon carbide under different delay time conditions and finds that the central temperature increase is maximized at a delay time (∆t) of 2 ms. In addition, the effect of a water layer on laser irradiation was considered, and it was found that the presence of a water layer has a significant impact on the temperature rise effect of the laser irradiation process. This research provides a theoretical basis for understanding and predicting the effects of nanosecond-millisecond combined pulse laser irradiation on silicon carbide, which is of great significance for exploring the application of high-performance silicon carbide materials under extreme conditions.