采用纳秒激光脉冲对铜金属进行了打孔实验, 对微孔形貌进行了观察并对其热力学过程进行了相应的分析。 研究表明, 微孔的形貌是由凹坑和周围隆起组成, 坑深随着脉冲能量的增加而增加。 热力学分析表明, 激光辐照金属打孔需要两个基本条件: 一是激光脉冲能量的沉积, 使金属材料发生熔化、 汽化以及电离等相变, 使得材料更容易去除; 激光等离子体作为二次热源会更有效把激光脉冲能量耦合到金属表面; 二是激光等离子体的冲击波效应, 这种效应会把发生相变的材料有效及时排出, 从而有效形成微孔。

The laser drilling experiment was carried out on the copper surface by ns laser pulse, then the micro-morphology of the micro-hole was observed and the thermodynamic process was analyzed accordingly. The research results show that micro-hole is made of the pit in the center and surrounding uplift. The pit becomes deeper with the incident laser pulse energy. The thermodynamic analysis indicates that laser drilling on the metal requires two basic conditions: the first is the deposition of laser pulse energy, which makes the occurrence of melting, vaporization and ionization. Such phase transition can make the materials easy to remove and the laser plasma can accelerate the laser pulse energy deposition as the secondary heat source. The second condition is the production of the laser plasma shock wave, it can eject the materials of phase transition effectively and timely, thus the micro hole can be formed.