The influence of temporal pulse train modulation during laser percussion drilling
The influence of temporal pulse train modulation during laser percussion drilling
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DOI：
10.1016/s0143-8166(01)00008-2
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发表时间：
2001-03-01
影响因子：
4.6
通讯作者：
Byrd, PJ
中科院分区：
文献类型：
--
作者：
Low, DKY;Li, L;Byrd, PJ
研究发现，激光冲击钻孔过程中的时间脉冲序列调制会对材料喷射过程产生显着变化。特别是，在被称为顺序脉冲传输模式控制（SPDPC）的时间脉冲串整形技术和正常传输模式（NDP）之间观察到材料喷射过程的明显差异，其中连续激光脉冲的参数是恒定的。由于 SPDPC 钻孔中向上材料去除率降低，飞溅沉积面积从大约 6.7 减少到 2.7 mm(2)。此外，孔底熔体层厚度也显着增加，从11-61μm增加到18-369μm。这种变化被认为是由于与 SPDPC 方法相关的光束突破之前的低激光脉冲强度造成的。据观察，使用线性增加的 SPDPC 方法增加了向下的材料去除率，从 NDP 钻孔中观察到的 20% 到 28%，增加到 34%-39%。 SPDPC 钻孔中向下材料喷射机制的这种增加被认为主要是由于束突破开始之前产生的尖盲孔轮廓。这项工作表明，调制激光冲击钻孔中的整个脉冲序列可以控制材料喷射过程。此外，SPDPC 技术的基本要素是根据能量沉积速率和总脉冲串能量给出的。 (C) 2001 Elsevier Science Ltd. 保留所有权利。
The temporal pulse train modulation during laser percussion drilling was found to effect significant changes to the material ejection processes. In particular, distinct differences in the material ejection processes have been observed between a temporal pulse train shaping technique termed as sequential pulse delivery pattern control (SPDPC) and the normal delivery pattern (NDP), wherein the parameters of successive laser pulses were constant. Due to the reduced upward material removal fractions in SPDPC drilling, the spatter deposition area was reduced from approximately 6.7 to 2.7 mm(2). In addition, the melt layer thicknesses at the hole bottom were significantly increased from 11-61 to 18-369 mum. Such changes were identified as being due to the low laser pulse intensities before beam breakthrough associated with the SPDPC method. It was observed that the use of the linearly increasing SPDPC method increased the downward material removal fractions, from 20% to 28% observed in NDP drilling, to 34%-39%. Such an increase in the downward material ejection mechanism in SPDPC drilling was identified as being primarily due to the pointed blind-hole profile generated before the onset of beam breakthrough. The work has shown that modulating the entire pulse train in laser percussion drilling could control the material ejection processes. Furthermore, the fundamental elements of the SPDPC technique are given in terms of the rate of energy deposition and total pulse train energy. (C) 2001 Elsevier Science Ltd. All rights reserved.