[18a-Z04-1~11] 3.7 Laser processing

△ [18a-Z04-8] Dependence of pulse duration on dry laser peening effects in the femtosecond-to-picosecond regime

〇Itsuki Nishibata¹, Masayuki Yoshida¹, Yusuke Ito², Naohiko Sugita², Akio Hirose¹, Tomokazu Sano¹ (1.Osaka Univ., 2.Tokyo Univ.)

Keywords:ultrashort pulse laser, peening

The authors succeeded in improving the peening effect by changing the pulse width in the dry laser peening process. Under conditions where the laser energy is constant, 1 ps gave the best result in the femtosecond-to-picosecond regime. The cause of the results was shown to be a decrease in laser fluence under pulse width conditions of shorter than 1 ps and the thermal effect that increased as the pulse width increased. In high-intensity ultrashort pulse laser processing, it is important to consider not only the pulse width dependence of the metal but also the early plasma-laser interaction in the air.