How Laser Drilling Works
Laser drilling is just one of a number of processes that our Fiber Laser range is designed for. Many of the laser processes bear striking similarities, and it can sometimes be difficult to easily distinguish between them. For example, laser drilling and laser cutting are often used interchangeably. Below we have explored in depth the process of laser drilling, how it came about, and just why this process is so useful for various manufacturing industries.
What is laser drilling?
Laser drilling is the process of creating holes both large and small in a variety of different materials. Some holes are thru-holes, used for creating things such as air-cooling vents, while other holes are nothing more than small dents in a material to roughen it up for coating and gluing purposes.
Laser drilling does exactly what it says on the tin; it drills like any other conventional drill, except the process is done using a fiber laser beam. This beam can be precisely and accurately controlled, so that the beam intensity, duration, and heat output are always firmly under the user’s control.
This varying level of control and adaptability means that laser drilling can create holes of all different shapes and sizes, and can work with a great deal of materials, including various metals such as stainless steel and nickel, rubber, plastics, semi-conductors, composites, and other materials such as tough diamonds. Laser drilling is a non-contact process, meaning that, unlike conventional drills, the laser doesn’t physically touch the material it is working with itself, meaning that the only mark that is left is the hole that has been drilled. This, in turn, maintains the original quality of the material.
What is the laser drilling process?
One laser drilling machine is capable of adapting to a wide range of tasks and situations, so can create hundreds of holes of all different shapes and sizes across complex 3D structures of varying materials. While there are various laser drilling processes that use different levels of beam heat or duration, such as trepan laser drilling or percussion laser drilling, they all work in much the same way.
The particular area of the material that is being worked upon has a beam focused on it; the size of this focus spot will depend on how large a hole it is that you need. The intensity of the beam begins to melt the material, causing an excess of said material in the focus spot. This results in a high level of vapour pressure being created, and this pressure then pushes out the melted excess material, leaving a hole underneath.
Holes as small as 0.0004” in diameter can be created, and at a rate of between 0.3 and 3 holes per second, so the laser drilling process is quick, efficient, and, most importantly, extremely effective. The greater the pulse energy of the laser during the laser drilling process, then the more material there will be that is melted and vaporised. Since laser drilling was first coined as a concept, several other techniques have evolved from the basic method:
Single shot and percussion laser drilling
A single laser is used to produce the necessary hole or thru-hole. Multiple holes can be produced, one at a time, very quickly using this method. With percussion laser drilling, it is still only one beam that is used, but in much shorter bursts. This creates a much deeper and more precise hole.
Trepan laser drilling
Trepan laser drilling uses multiple lasers to produce the required hole. A single hole is at first created using percussion laser drilling, and then the laser enlarges, resulting in the hole enlarging too. The laser moves round in circles to enlarge the hole. The excess molten material falls out through the hole.
Helical laser drilling
Helical laser drilling is extremely similar to trepan laser drilling, with the difference being that no initial pilot hole is created. Instead, with helical laser drilling, the laser moves in circles from the outset and most of the excess material shoots upwards instead.
Which is the best laser drilling process to use?
The laser drilling process that you use is entirely dependent on the outcome that you are looking for. A single shot laser drilling process will be quicker than the helical laser drilling process, but the latter will produce holes with much more precision. If you’re unsure on exactly what process to use, just ask!
What materials and substances are involved in the laser drilling process?
In the laser drilling process, you will find that several different elements and materials are involved. You will, of course, have the laser beam itself, emitted from a nozzle close to the material that you are working with. As the laser beam hits the material, you will have active gas, expelled molten material, and material vapour being emitted from the new hole, as well as molten material within the hole itself.
What advantages does laser drilling have over conventional drilling methods?
Laser drilling offers a great number of benefits over other forms of drilling methods available on the market. Listing out these benefits gives us a clear indication of just how effectively laser drilling works:
- It is a non-contact process, which means that a minimal amount of distortion is caused to the material that the laser drilling process is being utilised for
- Most importantly to the user, laser drilling offers a high level of accuracy and control over beam intensity and duration and heat output, meaning it produces consistent results time and time again. The fact that the beam can be so accurately controlled means that laser drilling can be used for drilling shallow angles or even shaped holes
- Laser drilling can produce holes with small diameters and high aspect ratios, for tasks such as roughening up surfaces, or thru-holes for tasks such as creating air pressure vents
- One laser drilling machine is capable of completing multiple tasks, and can be easily programmed and automated to adapt to these various tasks. These various tasks may be that different materials need to be laser drilled, or it might even be different types of laser process. One laser machine can be used for laser welding and laser cutting
- One of the biggest benefits of laser drilling is that it increases production rates by allowing faster setup times and less tooling. Laser drilling is very effective at working quickly and efficiently
- Laser drilling is also an extremely flexible process, allows for changeovers for prototypes and small-batch manufacturing
- Some laser drilling systems can be used to drill several features into a material at one time
- One of laser drilling’s biggest benefits is that it can be used on a number of different materials, including various metals, plastic, and even diamond
The wide range of above benefits not only gives us further insight into how the laser drilling process works, but also why it has become such a vital part of the manufacturing process.
Why is laser drilling now used?
We are living in an age of innovation, and as people continue to innovate, products are getting smaller and more complex. Previously, holes with a 0.004” diameter (roughly the size of a human hair) were all that was required, and conventional drills were capable of this.
Now much smaller holes are needed, and laser drilling is often the only practical method for creating these tiny holes. This is especially true when large depth-to-diameter ratio holes are needed to be created, typically greater than 10:1.
This has meant that laser drilling has found uses in many industry, including the aerospace, medical, and automotive industries.
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