摘要
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 ablation resistance of composite material is usually characterized by ablation heat that laser energy is consumed per unit ablation mass. Whereas the characterization ignores the effects of laser parameters. Taking C/SiC composite material as an example, by using a program for the numerical simulation of laser ablation of composite material, the ablation heat of C/SiC composite material is computed for different laser parameters. Effects of intensity, repetitive frequency and duty radio are analyzed. The result indicates that ablation heat is mainly correlated with intensity and duty cycle of the irradiating laser beams. More intensive laser beam causes more severe ablation. Ablation of unit mass requires more than average incident energy if duty cycle of the laser pulses decreases. In addition, it is realized that the repetitive frequency rate of laser has minor effect on ablation as long as average beam intensity and duty cycle are fixed. For C/SiC material, introducing of some instabilities into laser beams would enhance the ablation process, which leads to low ablation heat.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2013年第11期132-136,共5页
Chinese Journal of Lasers
基金
激光与物质相互作用国家重点实验室基金(SKLLIM1102)
关键词
激光技术
烧蚀热
C
SIC复合材料
激光参数
不稳定性
laser techniques ablation heat
C/SiC composite materials laser parameters
instability
