I. Brief description
The material to be processed is subjected to a high-power density laser beam, causing it to rapidly heat up to its vaporization temperature and evaporate, forming a hole.
Laser drilling is a seminal laser processing technology and a primary application area in laser processing. It falls under the category of laser removal, also known as evaporation processing.
With the rapid advancement of modern industry and technology, the use of materials with high hardness and melting points has increased, and traditional processing methods are unable to meet certain process requirements.
Compared to conventional punching methods, laser drilling boasts several key advantages:
- It has a fast drilling speed, high efficiency, and good economic benefits.
- Laser drilling can achieve a large depth-to-diameter ratio.
- It can be performed on a wide range of materials, including hard, brittle, and soft materials.
- There is no tool loss in laser drilling.
- It is suitable for processing a large number of high-density group holes.
- Laser drilling can be used to machine small holes on the inclined surface of difficult-to-machine materials.
II. Advantage
Compared to traditional punching processes, the laser drilling machine has several advantages:
- It has a fast drilling speed, high efficiency, and a good economic benefit.
- It can achieve a large aspect ratio in drilling.
- It can be used on a wide range of materials, including hard, brittle, and soft materials.
- There is no tool loss during laser drilling.
- It is suitable for processing a large number of high-density group holes.
- The laser can be used to machine small holes on inclined surfaces of difficult-to-machine materials.
- Laser drilling has simple workpiece clamping requirements and can be easily integrated into automated production lines.
In addition, laser drilling can be used to make holes in complex shapes and can also be performed in a vacuum environment.
Laser drilling equipment
1) Laser generator for laser drilling
The laser is a crucial component of laser drilling equipment. Its primary role is to convert the energy supplied by the power system into laser energy with a specific conversion efficiency.
Based on the nature of the laser’s working substance, it can be classified into two types: gas laser and solid-state laser. Gas lasers used for drilling mainly include carbon dioxide lasers, while solid-state lasers used for drilling mainly consist of ruby lasers, neodymium glass lasers, and YAG lasers.
Carbon dioxide lasers have numerous unique advantages, such as higher conversion efficiency compared to other lasers and the ability to be absorbed by various non-metallic materials, such as plexiglass, plastic, wood, multi-layer composite sheets, and quartz glass. Additionally, CO2 lasers offer high power output compared to other lasers. When combined with other technologies, high-speed drilling with a maximum speed of 100 holes per second can be achieved, which is challenging for other types of lasers.
Despite these benefits, carbon dioxide lasers are less popular in laser drilling equipment due to the inconvenience of focusing and dimming, as well as a relatively large one-time investment in equipment.
Solid-state lasers are widely used in laser drilling due to their unique advantages, such as a short output wavelength, the ability to be transmitted by ordinary optical materials, and a compact and easy-to-use design with a lower price compared to the carbon dioxide laser.
2) Laser drilling machine tool
The laser drilling form is simple and versatile, a three-dimensional machine tool.
The motion in two dimensions is in the horizontal plane and represented by X and Y. The two axes are perpendicular to each other and the third Z axis is perpendicular to the Z-Y plane.
Each dimension can be controlled by a stepper motor, which moves the ball screw along the linear ball guide. The accuracy of the machine tool is dependent on the precision of the lead screw and the accuracy of the ball guide.
With the addition of a microprocessor system, the 3D machine tool can perform laser drilling on various holes in the plane and groups of holes in a specific range.
For processing a series of holes in pipe or barrel materials, the machine tool requires a five-dimensional function. In addition to the three dimensions mentioned previously, the added two dimensions include a 360-degree rotation of the X-Y plane (defined as the A-axis) and tilting of the X-Y plane from 0-90 degrees in the Z direction (defined as the B axis).
With various types of laser drilling available, the five-dimensional workbench can handle the job. To save on equipment investment, the B axis CNC can be changed to manual, which will save money and complete all punching tasks.
3) Laser drilling machine
Over the years, the development of laser drilling machines both domestically and internationally has been rapidly advancing.
The output power of lasers has gradually increased, the pulse width has become increasingly narrow, the frequency range has expanded, and other parameters are becoming more favorable for punching.
The control portion of the light guiding system and the laser drilling machine is becoming more flexible, allowing for the expansion of the punching range.
