Laser Welding Machine

Most of the modern day’s welding techniques have been in existence for nearly a century now, and some of the arc welding principles were guessed at as long as two centuries ago by the Russian discoverer of the electric arc. TIG, or tungsten inert gas, welding was developed before World War II, for example, and was expanded and refined in response to the need to manufacture many combat-ready aircraft with welds that would stand up the stress of flying in dogfights and bombing raids. Many technical improvements have been made in these welding methods over time, but the basic principles are still recognizably those used generations ago in factories, shipyards, and workshops.

Laser welding, on the other hand, is a relative newcomer to the welding scene. Just a few decades ago, laser welding machines had just been built for the first time, and were so problem-riddled and inconvenient that they were used for a handful of highly specialized applications only. Research and development has been brisk, however, and laser welding machines are now used in many places, from car factories to cigarette lighter manufacturers and all other types of metal fabrication operations. These welding machines have several unique features that make their welds different from those provided by more traditional welder.

Welding with a laser welding machine

A laser welding machine makes use of a beam of extremely concentrated light, generally outside the spectrum visible to the human eye, to heat the materials that are being welded. The beam’s light energy is converted to heat energy as it is absorbed by the metal it is focused on, and this heat, in turn, melts the metal and creates a weld. The problem with this picture is that laser energy is light, and metal tends to be reflective, so a good portion of the laser beam reflects away rather than being absorbed, so laser welding is no more energy-efficient than other types. It has several advantages that help to counterbalance this fact, however.

One characteristic of laser welds is that the welds are very narrow and precise. The extreme weld narrowness possible with laser welding machines means that the technique can be used for fine work as well. The two types of lasers that are used for welding most often are Nd:YAG and CO2 (carbon dioxide) lasers. Nd:YAG lasers have a relatively low energy output and produce a narrow, shallow weld at a high rate of speed.

Carbon dioxide laser welding machines, on the other hand, are very powerful can produce unique deep, narrow welds of very high quality, through a process known as “keyholing.” Keyholing involves focusing the laser at one point on the metal until a hole is formed, which fills with vaporized metal. This metal vapor absorbs huge amounts of energy very efficiently and transmits it as heat to the nearby metal. The laser can then be advanced, and the heat is so intense that the metal melts deeply but narrowly, flowing in to fill the cavity behind the laser (which started with the keyhole) and forming an extremely deep, narrow, strong weld. This procedure can be used on a wide range of metals such as carbon steels, stainless steel, aluminum, and titanium.

Laser welding machines come in all sizes – from huge industrial lasers to “micro-laser” welders (generally of the Nd:YAG configuration). The laser welding machine is slow to penetrate many industries due to ‘technical inertia’ and resistance to the unfamiliar, but given its unique welding properties, laser welding will probably continue to gain ground and become more accessible.