Traditional machining routes include mechanical cutting, thermal cutting (e.g., plasma/flame), and conventional laser cutting. Mechanical machining is contact-based; tool wear and cutting forces can induce micro-damage and deformation, limiting achievable precision and surface integrity. Thermal cutting is efficient for thick sections but typically produces large HAZ, residual stresses, and microcracks that reduce mechanical performance. Conventional laser processing, while versatile, may still suffer from relatively large HAZ and unstable performance on highly reflective or heat-sensitive materials.

As summarized in Fig. 3, WJGL uses water as the transmission medium and a concurrent coolant, significantly reducing HAZ and suppressing distortion and microcracking, thereby improving precision and edge/surface quality (see Fig. 4). Its advantages can be summarized as follows:

1. Low thermal damage and improved quality: The high specific heat capacity and continuous flow of water rapidly remove heat, limiting thermal accumulation and helping preserve microstructure and properties.

2. Enhanced focusing stability and energy utilization: Confinement within the jet reduces scattering and energy loss compared with free-space propagation, enabling higher energy density and more consistent processing—well suited to fine cutting, micro-drilling, and complex geometries.

3. Cleaner and safer operation: The water medium captures and removes fumes, particulates, and debris, reducing airborne contamination and improving occupational safety.

Specification

Application Share and Sector Distribution of Water-Jet Guided Laser (WJGL) Cutting Materials

Aerospace and Energy (≈30–35%)

This sector represents the largest share of WJGL applications. Typical materials include carbon fiber reinforced polymers (CFRP), aluminum matrix composites (Al MMC), and ceramic matrix composites (CMC). WJGL is particularly suitable for these materials due to its ability to minimize thermal damage and preserve mechanical properties when cutting thermally sensitive and anisotropic composites used in high-performance aerospace and energy structures.

Precision Instruments and Metallic Materials (≈25–30%)

A significant portion of WJGL usage is devoted to precision metal processing. Representative applications include engine blades manufactured from Ni-based superalloys (e.g., Inconel 718, Haynes 188), titanium alloys (Ti-6Al-4V), and high-precision components such as wristwatch parts made from Cu, Al, and Ti. The technology enables high dimensional accuracy, narrow kerf widths, and superior surface quality.

Semiconductors and Microelectronics (≈20–25%)

In the semiconductor and microelectronics sector, WJGL is widely applied to the cutting of crystalline and brittle materials, including silicon wafers, diamonds, and photovoltaic materials such as Si and GaAs. Its capability to suppress micro-cracks, chipping, and subsurface damage makes it well suited for high-precision wafer dicing and micro-scale fabrication.

Medical Components (≈10–15%)

Although smaller in overall share, medical applications are of high technological value. WJGL is mainly used for fabricating cardiovascular flat stents from biocompatible alloys such as CoCr, NiTi, Cr-Pt, and magnesium alloys. The process meets stringent requirements for ultra-fine features, tight tolerances, and minimal heat-affected zones critical to medical device performance.

Overall, the sectoral distribution demonstrates that WJGL cutting is predominantly employed in advanced manufacturing domains where high precision, low thermal impact, and excellent material integrity are essential.

Water-Jet Guided Laser (WJGL) FAQ

 

1) What is Water-Jet Guided Laser (WJGL) machining?

WJGL is a laser processing method in which the laser beam is coupled into a micro water jet. The water jet acts as both a beam-guiding medium and a cooling/debris-removal medium, enabling high precision with reduced thermal damage.

2) How does WJGL work?

WJGL relies on total internal reflection at the water–air interface. Because water and air have different refractive indices, the laser can be confined and guided within the water column—similar to a “liquid optical fiber”—and delivered stably to the machining zone.

3) Why does WJGL reduce the heat-affected zone (HAZ)?

The continuously flowing water removes heat efficiently due to its high heat capacity. This suppresses heat accumulation, reducing HAZ, distortion, and microcracking.