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复合材料的抗激光烧蚀性能一般用烧蚀单位质量所需的激光能量(即烧蚀热)表征,这种表征方式忽略了激光强度与稳定性的影响。以C/SiC复合材料为例,在材料表面热化学平衡分析的基础上,基于复合材料激光烧蚀效应数值模拟程序,计算了不同参数下激光辐照复合材料的烧蚀热,分析了强度、频率、占空比等激光参数对烧蚀效率的影响。研究结果表明,烧蚀热与占空比、激光强度有关,与重复频率关系不大。激光强度越大,烧蚀热越小;占空比减小,单位烧蚀质量所需的能量增大,即烧蚀热随占空比的减小而增大;在平均功率密度及占空比相同的前提下,不同重复频率对加热影响很小。对C/SiC复合材料的激光烧蚀,相同平均功率密度下,激光强度不稳定性越大,烧蚀热的期望值越小。
The laser ablation resistance of composites is generally characterized by the laser energy required to ablate the mass of the unit (ie, ablation heat), a characteristic that ignores the effects of laser intensity and stability. Taking C / SiC composites as an example, based on the thermochemical equilibrium analysis of the material surface, the ablation heats of the laser irradiated composites under different parameters were calculated based on the laser ablation numerical simulation program of the composites. The intensity, Effect of laser parameters such as frequency and duty cycle on ablation efficiency. The results show that the heat of ablation is related to the duty ratio and the laser intensity, and has little to do with the repetition frequency. The larger the laser intensity, the smaller the heat of ablation. The smaller the duty cycle, the larger the energy required for unit mass ablation, that is, the heat of ablation increases with decreasing duty cycle. When the average power density and duty cycle Under the same premise, different repetition frequency has little effect on heating. For laser ablation of C / SiC composites, with the same average power density, the greater the instability of laser intensity, the smaller the expected value of ablation heat.