【摘要】 随着飞秒激光加工精度和性能要求的不断提高，实现加工过程的实时优化已成为提升加工质量与效率的核心挑战。等离子体荧光光谱及其电子参数已被广泛应用于实时监测，但二者在不同加工条件下的监测稳定性对比尚未得到充分研究。鉴于此，本团队探索了不同脉冲能量、扫描速度和扫描次数下，光丝诱导碳化硅陶瓷基复合材料等离子体辐射的荧光谱线强度及等离子体参数的变化规律，并对比分析了二者在光丝加工过程中监测V形槽宽的稳定性。实验结果表明，相较于直接读取的谱线强度，通过多条谱线强度计算的电子温度在不同加工条件下，均能与V形槽宽保持良好的映射关系，表现出更稳定的加工监测能力。本研究对于推动基于等离子体光学辐射的智能实时加工优化具有重要的指导意义。更多还原

【Abstract】 Objective Femtosecond laser filament processing has attracted significant attention due to its unique advantages, such as high precision, “cold processing” characteristics, and the capability to fabricate high-aspect-ratio structures and two-dimensional structures on large-curvature surfaces. However, the complexity of processing parameters, coupled with increasing demands for high precision, high quality, and adaptability to rapid product iterations, poses substantial challenges. Real-time optimization of the machining process has thus become essential for enhancing both processing quality and efficiency. Although plasma fluorescence spectra and plasma electron parameters are widely used for real-time monitoring, a comparative analysis of their monitoring stability under various processing conditions remains underexplored. This study aims to systematically compare the monitoring stability of plasma fluorescence spectral line intensities and plasma electron parameters during femtosecond laser filament grooving of silicon carbide ceramic matrix composites(SiC CMCs), providing important insights for intelligent and real-time machining process optimization based on plasma optical radiation.Methods The experimental setup involved a Ti∶sapphire chirped-pulse amplification(CPA) laser system generating 48 fs pulses at a central wavelength of 800 nm and a repetition rate of 1 kHz. The laser was focused to form a filament for grooving SiC CMC samples. Plasma emission during processing was collected via a lens system and analyzed using a spectrometer coupled with an intensified charge-coupled device(ICCD). Key parameters including pulse energy, scanning speed, and number of scanning passes were varied. The V-shape groove width was characterized metallographically, while spectral line intensities and electron parameters(temperature and density) were derived from selected silicon emission lines using the Boltzmann plot method and the Stark broadening method. The stability of the monitoring process was evaluated by establishing mapping relationships between the monitoring parameters(line intensity and electron temperature) and the V-shape groove width under different processing conditions.Results and Discussions Under varying pulse energies, both spectral line intensity and electron temperature increased with energy; however, atomic line intensities decreased at 1.5 mJ due to suppressed recombination at higher plasma temperatures. Electron temperature exhibited a stronger linear correlation with groove width(R~2=0.8846) than did spectral line intensity(R~2=0.5880). At different scanning speeds, the V-shape groove width decreased as speed increased. A Sigmoidal relationship was identified between electron temperature and groove width, a relationship that more accurately reflected process dynamics than the linear relation between spectral line intensity and groove width. Under multiple scanning passes, both electron temperature and density increased due to defect accumulation and enhanced ionization, while spectral line intensity decreased owing to signal occlusion caused by the deepening groove. Across all conditions, electron parameters demonstrated superior stability and correlation to morphological outcomes.Conclusions This study confirms that plasma electron parameters, particularly electron temperature, provide more stable and reliable monitoring for V-shape groove width during femtosecond laser filament processing of SiC CMCs compared to direct spectral line intensity. The electron parameters maintained strong functional relationships with groove morphology under varying pulse energies, scanning speeds, and number of scanning passes—and were less affected by signal interference and process-related irregularities. These findings support the use of electron temperature as a robust input for closed-loop control in real-time laser processing, thereby promoting higher precision and intelligent optimization in industrial applications.更多还原