Effect of pulse duration and repetition rate of nanosecond laser on material removal under constant processing time and power consumption

山本 恵輔*; 小菅 淳 ; 中嶋 隆*

Yamamoto, Keisuke*; Kosuge, Atsushi; Nakajima, Takashi*

To study the effect of pulse duration and repetition rate of nanosecond laser on material removal through laser ablation, the pulse duration or repetition rate is usually varied under the constant laser pulse energy or fluence, so that the dynamics induced by a single laser pulse is similar if the heat accumulation effect may be neglected. A more practical and meaningful comparison would be to vary those parameters under the constant laser power, scan speed, and line pitch, which guarantees the constant processing time and power consumption. In this work we vary the pulse duration and repetition rate at the constant laser power (17.4 W), scan speed (200 or 1000 mm/s), and line pitch (10 m), to study the material removal and surface morphology of the stainless steel target. Interestingly, it turns out that both pulse duration and repetition rate influence the material removal, and there exists optimal values of pulse duration and repetition rate under the constant processing time and power consumption to achieve the maximum material removal.