激光冲击效应下的力学电化学微细刻蚀加工

在所构建的纳秒脉冲激光电化学加工系统中,利用激光辐照和脉冲电化学刻蚀复合的方法对铝合金进行了加工试验,研究了激光穿过溶液作用于物质时产生的力效应和电化学效应对加工质量的影响.试验结果表明:高能脉冲激光透过电解液辐照在工件表面时,激光在电解液中产生的冲击波力效应和射流冲击力效应会使工件发生弹性变形,从而改变电极电势,提高电流密度,加速了对工件的刻蚀.激光产生的力效应能够去除加工区的钝化层,使其发生电化学反应,而非加工区不发生反应,从而显著增强了电化学的定域蚀除能力.最后,利用力学电化学效应,在浓度为0.5 mol/L的NaNO3溶液中实现了线宽140 μm左右、深宽比较大的微细刻蚀加工,获得了较好的加工质量和成形精度.

Mechanical-electrochemical micro-etching under laser shock effect

An aluminum alloy workpiece was etched by a compound processing of laser and electrochemistry in an experimental system established,and the influence of mechanic effect caused by a laser shock and an electrochemical effect on the process quality was investigated.The results show that when a high-energy pulsed laser irradiates on the metal workpiece in the solution,it will take the elastic deformation by the jet impact and the shock wave force caused by the laser.Under the stress of the laser shock wave,the potential electrode is changed,current density is increased,and the electrochemical corrosion of metallic materials is accelerated.Moreover,the mechanics effect of laser shock could remove the passivation layer on the workpiece surface irradiated by the laser,and the material at this zone is eroded and removed.However,the other zone material could not be corroded with the protection of the passivation layer,which enhances the locally etching ability of electrochemical machining significantly.Finally,the compound machining of the laser shock and electrochemical corrosion was used to achieve a micro-etching with a high aspect ratio and a line width of 140 μm in the NaNO3 solution with a concentration of 0.5 mol/L,which obtains good processing quality and satisfactory shaping precision.