Comparative study on precision machining of tungsten alloy by femtosecond laser and water-jet guided laser

Tungsten alloys serve as core structural materials for high-end strategic sectors including aerospace infrastructure, nuclear power systems, and defense engineering due to their superior combined mechanical and thermophysical characteristics. However, their intrinsically high melting point and extreme hardness impose formidable limitations on high-precision micromachining, severely restricting the high-quality fabrication of tungsten alloy micro-components. Herein, femtosecond laser (fs laser) and water-jet guided laser (WJGL) were selected to investigate the precision micromachining of tungsten alloy. Since fs laser and WJGL operate under inherently different conditions (e.g., pulse duration, wavelength, and cooling mechanism), the present comparison was conducted under their respective optimized processing parameters. The comparative results demonstrate that WJGL has notable advantages over fs laser in groove taper quality, surface cleanliness, and processing efficiency. With systematic optimization of process parameters, it enables high-precision fabrication of tungsten alloys and yields a low surface roughness of 2.49 μm, a taper angle of 0.4°, and a material removal rate (MRR) of 21 × 10 -3 mm 3 /s. Further elemental composition and morphological analysis reveal that WJGL effectively suppresses oxidation during processing, as evidenced by an oxygen content of 3.75 %, far below the 16.84 % of fs laser-processed counterparts. Such efficient oxidation suppression and dramatic reduction of recast layers are fundamentally attributed to the continuous cooling and rinsing of the water jet. Finally, high-quality tungsten alloy micro-probes were fabricated via WJGL, they exhibit intact and sharp cutting edges, negligible edge chipping, suppressed heat-affected zones (HAZs), and a dimensional tolerance within 0.46 %. This work provides an efficient and superior solution for the precision machining of hard and brittle materials.