Experimental study on water-jet guided laser microhole drilling of tungsten alloy

Abstract

Tungsten alloy is widely used in aerospace, nuclear energy, and national defense due to its high density, high strength, and high melting point. However, conventional machining of micro-holes in tungsten alloy is hindered by severe tool wear, thermal damage, and low efficiency. To address these challenges, this study applies water-jet guided laser (WJGL) technology to the micro-hole drilling of tungsten alloy. The influence of pulse energy, repetition frequency, and water pressure on hole taper and processing time was systematically investigated. Under the optimized parameters (pulse energy: 3.6 mJ, scanning speed: 5 mm/s, repetition frequency: 7 kHz, water pressure: 20 MPa), micro-holes with a taper angle as low as 0.32° were achieved within approximately 26 s. The microscopic morphology and elemental analysis reveal that the WJGL-machined surfaces exhibit high cleanliness, are effectively free of recast layers, and show markedly suppressed oxidation. Multi-hole array experiments further confirm the high repeatability and consistency of the process. These findings demonstrate that water-jet guided laser technology offers a promising solution for high-quality, high-efficiency micro-hole drilling in tungsten alloy.