by Michael Shade, IQS Editor
Ever wonder how the stimulation of a carbon dioxide or neodymium-aluminum-garnet lasing material with either electrical discharges or radio frequency resonators can be used to facilitate industrial laser cutting or surface finishing processes? If you’re anything like me, your answer is probably an emphatic “Huh?” There’s something about lasers and their operating principles that seem opaque and distant to me. I’d bet that most people I know are aware that “laser” is an acronym, but I doubt that many of them know what it stands for, and even fewer of them could describe how lasers work. The trouble may be that lasers don’t enjoy very accurate representation in media, or it may be that our encounters with lasers in daily life are not very personal or direct. But it’s clear that we benefit from their use in many ways.
It’s a little surprising that the common denominator of familiarity with lasers and how they work isn’t higher considering how frequently and widely they’re used in modern life. My computer’s disc drive wouldn’t work without its optical disc reading drive, nor would my CD or DVD players. I wouldn’t be writing this article if it weren’t for the laser in my optical mouse. All of these devices have something in common: they use amplified light to achieve something. That light amplification is the first part of the laser acronym; the full acronym is Light Amplification by Stimulated Emission of Radiation. The Stimulated Emission part refers to the process stimulating a substance with an exciting force that causes the substance to emit radiation in the form of light. That light gets bounced around by mirrors and focused with a lens, resulting in a highly-amplified beam of monochromatic light.
Different processes call for different kinds of equipment. It goes without saying that the kind of laser device found in my optical mouse isn’t suitable for burning through metal. But the only functional difference between the laser in my mouse and a laser used to cut through metal is the intensity of the beam of light. In theory, a strong enough laser beam could be used to cut through anything. In fact, in recent years strong lasers have been applied in experiment contexts for the purposes of shooting down missiles. In industry, though, use of medium-strength lasers is far from experimental. On the contrary, the use of lasers for cutting and surface treatment is widespread.
Why has industry chosen the laser as a cutting tool? Take a look at the image above. Would you use a saw to cut those shapes out of sheet metal? You would need a tool that’s capable of precisely cutting without bending or warping the workpiece. Custom laser cutting equipment is chosen over other cutting methods because it can cut precisely without deforming workpieces. An added benefit is that it’s capable of creating clean cuts. Especially on thin workpieces, lasers create clean cuts that often require minimal finishing or additional processing. Lasers can be used to cut through many varieties of steel and aluminum as well as plastic in some cases.
Another tremendous benefit of laser cutting is that it can be controlled by CNC software, which makes the cutting process that much more precise and repeatable. This means that a company can submit concept drawings of the parts they need, and the finished products created by the laser cutting equipment will be indistinguishable from their drawings. One limitation of laser cutting is that its effectiveness becomes limited as the thickness of a workpiece is increases. For example, laser cutting wouldn’t be a good choice for cutting very thick plating or tubing. However, it’s not likely that those kinds of cutting jobs would call for high levels of precision in the first place.
Industrial lasers are only going to increase in prominence as technology improves and as the demand for complex metal fabrications persists. They make an undeniable contribution to manufacturing, and they make the production of all kinds of important products possible.