Patterned Laser Ablation of Microgrooves with Controllable Cross-Sections

Fabricating precision microgrooves with controllable cross-sections on difficult-to-machine materials is significantly valuable but still challenging. Herein, a patterned laser-induced microjet-assisted ablation method for cross-sectional profiles controllable laser micromachining is proposed. During the liquid-assisted laser ablation process, debris and bubbles that may disturb the laser energy deposition can be instantaneously expelled by a directional laser-induced microjet. The Gaussian laser spot is spatially modulated into specific geometric shapes, such as triangles, to tune locally deposited laser energy to carve microgrooves with designed cross-sections. To achieve customized microgrooves efficiently, a reliable geometrical model based on the ablation threshold theory is developed to guide the processing parameter selection, including the laser spot shape, polarization, pulse energy, and scanning strategies. The simulation and experimental results confirm that this method achieves the decoupled control of the groove depth and width in a single-path laser ablation process. Using this method, the design and manufacturing of microgrooves with controllable cross-sections on single crystalline silicon carbide are demonstrated. The patterned laser-induced microjet-assisted ablation method provides a new route for fabricating precision microgrooves with controllable cross-sections on difficult-to-machine materials.

Automated summary

This study proposes a patterned laser-induced microjet-assisted ablation method for fabricating precision microgrooves with controllable cross-sections on difficult-to-machine materials. The method utilizes a directional laser-induced microjet to expel debris and bubbles during the laser ablation process and spatially modulates the laser spot into specific geometric shapes to control the deposited laser energy for carving microgrooves with designed cross-sections. A reliable geometrical model based on the ablation threshold theory is developed to guide the processing parameter selection, and the method achieves decoupled control of groove depth and width in a single-path laser ablation process. The demonstration on single crystalline silicon carbide validates the effectiveness of this method. This patterned laser-induced microjet-assisted ablation method provides a new route for fabricating precision microgrooves with controllable cross-sections on difficult-to-machine materials.