复合脉冲深度激光打孔的实验研究

摘要

To further improve the velocity of deep laser drilling in thick metal plate,aiming at 5mm thick stainless steel plate,laser drilling method of long pulse laser with high pulse energy superposed by short pulse laser with high peak power was put forward.The theoretical model of laser drilling by superposed pulsed lasers was established.The function of long pulse laser with high pulse energy was to melt metals,while the removal of metal melted things relied mainly on short pulse laser of high peak power.The drilling effects under different laser parameters(pulse energy,pulse width and drilling method)were studied.The results show that,compared with laser drilling by single long pulse,laser drilling by the superposed pulse can substantially reduce the drilling time.For long pulse of 2ms pulse width and 2.9J pulse energy,the drilling velocity of superposed pulsed lasers increases by 2.3 times while the energy cost reduces 20％.And the larger the pulse energy is,the narrower the pulse width is,the faster the drilling velocity becomes.The study provides a basis for laser selection in laser drilling by the superposed pulsed lasers.%为了进一步提高激光在金属厚板上深度打孔的速率,针对5mm厚不锈钢板,采用高峰值功率短脉冲串叠加大能量长脉冲的双光束复合激光打孔方法,建立了复合脉冲激光打孔的理论模型,提出大能量长脉冲激光束的主要作用是熔化金属,排出金属熔融物主要靠高峰值功率密度的激光脉冲串,并研究了脉冲能量、脉冲宽度、打孔方式等不同激光参量下的激光打孔效果.结果表明,与长脉冲激光单独激光打孔相比,复合脉冲激光打孔能大幅减小穿孔时间,对脉宽2ms、单脉冲能量2.9J的长脉冲,复合脉冲打孔速率提高2.3倍,所需能量减少20％,且脉冲能量越大,脉冲宽度越窄,打孔速率越快.此研究为复合脉冲打孔的激光器选择提供了依据.