Conventional ignition methods are proving to be ineffective for low-sensitivity energetic materials,highlighting the need to investigate alternative ignition systems,such as laser-based techniques.Over the past decade...Conventional ignition methods are proving to be ineffective for low-sensitivity energetic materials,highlighting the need to investigate alternative ignition systems,such as laser-based techniques.Over the past decade,lasers have emerged as a promising solution,providing focused energy beams for controllable,efficient,and reliable ignition in the field of energetic materials.This study presents a comparative analysis of two state-of-the-art ignition approaches:direct laser ignition and laser-driven flyer ignition.Experiments were performed using a Neodymium-doped Yttrium Aluminum Garnet(Nd:YAG)laser at different energy beam levels to systematically evaluate ignition onset.In the direct laser ignition test setup,the laser beam was applied directly to the energetic tested material,while laserdriven flyer ignition utilized 40 and 100μm aluminum foils,propelled at velocities ranging from 300 to 1250 m/s.Comparative analysis with the Lawrence and Trott model substantiated the velocity data and provided insight into the ignition mechanisms.Experimental results indicate that the ignition time for the laser-driven flyer method was significantly shorter,with the pyrotechnic composition achieving complete combustion faster compared to direct laser ignition.Moreover,precise ignition thresholds were determined for both methods,providing critical parameters for optimizing ignition systems in energetic materials.This work elucidates the advantages and limitations of each technique while advancing next-generation ignition technology,enhancing the reliability and safety of propulsion systems.展开更多
This paper deals with the interaction of femtosecond laser with strain dependent high dielectric material. For this investigation, ferroelectric material like BaTiO<sub>3</sub> has been chosen because of c...This paper deals with the interaction of femtosecond laser with strain dependent high dielectric material. For this investigation, ferroelectric material like BaTiO<sub>3</sub> has been chosen because of centrosymmetric structure. Due to irradiation of laser light, the micro-structure of BaTiO<sub>3</sub> is found to change along the direction of heat propagation. SEM and AFM tools have been used to detect the morphology and roughness of the femotosecond laser treated BaTiO<sub>3</sub>. The change of morphology and surface behavior depends upon the laser fluence and intensity of laser light. The maximum change in morphology has been observed at a higher laser fluence.展开更多
文摘Conventional ignition methods are proving to be ineffective for low-sensitivity energetic materials,highlighting the need to investigate alternative ignition systems,such as laser-based techniques.Over the past decade,lasers have emerged as a promising solution,providing focused energy beams for controllable,efficient,and reliable ignition in the field of energetic materials.This study presents a comparative analysis of two state-of-the-art ignition approaches:direct laser ignition and laser-driven flyer ignition.Experiments were performed using a Neodymium-doped Yttrium Aluminum Garnet(Nd:YAG)laser at different energy beam levels to systematically evaluate ignition onset.In the direct laser ignition test setup,the laser beam was applied directly to the energetic tested material,while laserdriven flyer ignition utilized 40 and 100μm aluminum foils,propelled at velocities ranging from 300 to 1250 m/s.Comparative analysis with the Lawrence and Trott model substantiated the velocity data and provided insight into the ignition mechanisms.Experimental results indicate that the ignition time for the laser-driven flyer method was significantly shorter,with the pyrotechnic composition achieving complete combustion faster compared to direct laser ignition.Moreover,precise ignition thresholds were determined for both methods,providing critical parameters for optimizing ignition systems in energetic materials.This work elucidates the advantages and limitations of each technique while advancing next-generation ignition technology,enhancing the reliability and safety of propulsion systems.
文摘This paper deals with the interaction of femtosecond laser with strain dependent high dielectric material. For this investigation, ferroelectric material like BaTiO<sub>3</sub> has been chosen because of centrosymmetric structure. Due to irradiation of laser light, the micro-structure of BaTiO<sub>3</sub> is found to change along the direction of heat propagation. SEM and AFM tools have been used to detect the morphology and roughness of the femotosecond laser treated BaTiO<sub>3</sub>. The change of morphology and surface behavior depends upon the laser fluence and intensity of laser light. The maximum change in morphology has been observed at a higher laser fluence.
