Lasers make welding mobile
Whenever a job involves joining two components, there’s generally no way to avoid welding. The technique is well-proven, with a range of solutions that range from the simple to the relatively complex. Laser welding plays a particularly special role in industry, as it allows the work to be performed on a mobile basis, taking the welder directly where the work is needed to reduce costs and increase efficiency.
© Wolfram Scholl
The history of welding dates back to well before industrialisation. Wikipedia reports the first attempts at welding as having taken place in the third millennium BC; and “fire and hammer” welding techniques are believed to have originated in Asia Minor in the 15th century BC. The Iron Pillar of Delhi, which is around seven metres high and weighs 6.5 tonnes, is often named as an early example of works that were creating using the welder’s craft: it consists of 98% wrought iron and survived for around 1,600 years with no significant corrosion. Presumably, the monument was produced with temperatures that would have reached around 1,200 degrees Celsius. However, welding really only got into its stride in the nineteenth century, following the invention of arc welding.
All kinds of welding are widespread in all high-tech industries and an essential part of the production process.
There are many different welding processes in current use, from simple through to the relatively complex. The technology is highly advanced and, in a professional context, it requires extensive knowledge of the characteristics of a wide range of different materials. Generally, pieces are joined at high temperatures, so that the materials involved melt together – which is the difference between low-temperature soldering. Additional materials are generally used to ensure a stable, long-lasting weld. Occasionally, pieces are combined merely by using pressure. When the term welding is used, it generally refers to metals; however, plastics or glass can also be combined. In industry, welding is a vitally important process, and nearly all sectors join metals and other materials – from the automotive industry through to aircraft construction.
Mobile welding reduces costs
Laser welding offers one substantial benefit over all other kinds of welding: the process can be made mobile. The piece itself does not need to be touched whatsoever before being welded. In laser welding, a highly-focused laser beam applies the necessary heat energy to the joint, thereby heating the material directly. In many cases, additional materials to join the materials are not required; instead, an inert or protective gas is used to prevent unwanted chemical reactions. This form of welding is particularly accurate and produces extremely fine, solid welds, which can be reproduced as many times as necessary thanks to the use of automated controls.
An example application for mobile laser welding – Phoenix Laser Solutions, Dave Learn
Suppliers in the light engineering sector, such as Alphalaser from Puchheim near Munich produce mobile systems for laser welding that significantly simplify the repair process. The use of these lasers is independent of the location where the work takes place: repairs can also be undertaken directly at the customer’s premises, restoring large, worn machine components, moulds that weigh several tonnes, or fixed tooling,” writes the manufacturer on its website. This video shows what it looks like in practice. Another, slow-motion video published by the business shows how the material behaves when a laser pulse is applied to it. Devices such as these are used everywhere that mobility and flexibility are required, generating significant time savings and improving industrial efficiency, as there is no need to dismantle or move machinery or components. Instead, the components are assembled or repaired on site.
Advantages of laser welding for the aviation sector
Mobile laser welding systems also play a significant role in the aviation industry. The ARTS calendar page for June was shot by our photographer, Wolfram Schroll, at Airbus in Ottobrunn. Airbus has invested in laser welding technology to complement or replace traditional welding technologies. Currently, assemblies for the A318, A340-600 and A380 passenger aircraft are produced using laser welding technologies. For example, individual turbine blades can be repaired and returned to working order. However, companies are constantly faced with the challenge of selecting the right materials. For example, some grades of aluminium used in the aerospace industry have a tendency to become brittle under extreme heat. A scientific article highlights the suitability of laser welding in the construction of a regional aircraft, identifying benefits over traditional, riveted production techniques: it is faster, saves weight, and uses less energy.
Automotive manufacturers use lasers for welding
Laser welding is also becoming increasingly established in the automotive industry in comparison to traditional welding techniques, in all aspects of production from electrics through to engine manufacture. The same benefits apply in this sector – from the precision of the welds through to the limitless reproducibility of each step in the process. Moreover, the lasers can be used to cut and mark components as well as for welding.
Unlike crude, traditional equipment, laser welding can also be used on a small scale. Micro laser welding is the watchword when it comes to working with the smallest components. The process is similar to large format laser welding; however, less energy is used and greater accuracy is achieved. Other welding processes are also used in this small-scale environment.
The micro laser welding technique allows the smallest components to be worked on - LaserStarTV
Joke Technology, which is based in Bergisch Gladbach near Cologne, has recently expanded its product portfolio to include a laser welder called Eneskalaser, which has been developed for precise, accurate work in tooling and mould-making. The feature list of this tool reads like an electronics brochure: touch-screen display, joystick, Wi-Fi, and interfaces including HDMI come as standard. Welding profiles and parameters can be saved for later use.
Laser as a key to atomic fusion?
The energy generation sector has discovered an entirely different application for lasers; more specifically, in nuclear fusion research. At the National Ignition Facility at the Lawrence Livermore National Laboratory in California, experiments are underway to apply heat and pressure to hydrogen with a view to achieving so-called internal confinement fusion. This requires the energy of many high-performance lasers to trigger a chemical reaction that resembles the chemical processes that take place inside the sun. As an aside, another form of fundamental research is also underway at the same time – for example, the scientists would like to discover the secrets that lie behind a supernova.