Ablation Threshold and Interaction of Cemented Carbide Ablated by Ultrafast Laser

In this study, we used an ultrafast laser with a wavelength of 1026 nm with the aim of analyzing the ablation threshold and morphologies of the irradiated surfaces of cemented carbide by varying the pulse duration and number of laser pulses. Specifically, we used pulse durations of 0.2, 2, and 10 ps and performed both gentle and strong ablations. For the same wavelength, laser pulse energy, and number of laser pulses, the lowest ablation threshold was 0.2 ps. When we performed a gentle ablation, we observed laser-induced periodic surface structures (LIPSSs) on the entire irradiated surface for all pulse durations. Thus, the pulse duration did not appear to affect the formation of LIPSSs. Strong ablation caused ridges to form at irradiated area outside. When the pulse duration increased, larger ridges were formed, whereas when the pulse duration decreased, coarser ridges were formed. The results obtained by using the ultrafast laser is expected to be helpful in the machining of cemented carbide.