Laser-Induced Ignition and Combustion of Individual Aluminum Particles Below 10 μm by Microscopic High-Speed Cinematography
| Autor: | Fengting Hou, Shengji Li, Yue Wang, Xuefeng Huang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
microscopic high-speed cinematography Laser ignition chemistry.chemical_element Bioengineering 02 engineering and technology lcsh:Chemical technology Combustion 01 natural sciences Thermal expansion law.invention submicron particle lcsh:Chemistry law Aluminium 0103 physical sciences Chemical Engineering (miscellaneous) combustion mechanism lcsh:TP1-1185 Laser power scaling Composite material 010304 chemical physics Process Chemistry and Technology individual aluminum Thermite laser ignition 021001 nanoscience & nanotechnology Evaporation (deposition) Ignition system lcsh:QD1-999 chemistry 0210 nano-technology |
| Zdroj: | Processes Volume 8 Issue 3 Processes, Vol 8, Iss 3, p 280 (2020) |
| ISSN: | 2227-9717 |
| DOI: | 10.3390/pr8030280 |
| Popis: | Metal aluminum has been widely used as an ingredient in propellant, gunpowder and thermite, but there is less understanding of the combustion mechanism of aluminum particles from submicron to several microns in diameter. This paper proposes to experimentally investigate the ignition and combustion characteristics of individual aluminum particles below 10 &mu m. A specific in situ diagnostic experimental apparatus was first designed for directly observing the ignition and combustion behaviors of individual aluminum particles, with a submicrometer spatial resolution and a temporal resolution of tens of microseconds. Direct observation through microscopic high-speed cinematography demonstrated that, when heated by a continuous laser, individual aluminum particles thermally expanded, followed by shell rupture the molten aluminum core overflowed and evaporated, leading to ignition and combustion. Further results showed that, when the laser power densities were gradually increased (5.88, 7.56 and 8.81 × 105 W/cm2), the durations of thermal expansion, melting and evaporation were shortened. The required time for the aluminum particles to expand to 150% of their initial diameter was shortened (34 s, 0.34 s and 0.0125 s, respectively). This study will be beneficial to further extend the investigation of other individual metal particles and reveal their combustion mechanism by direct observation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|