How is laser welding better than TIG?

Arc welding as a production process took a long time to become established, but has nevertheless been around since the 1940s.  Although the laser was only invented in 1960, it quickly became established as a production process and by the 1980s was starting to be used in high volume manufacturing.  Recent advances which have improved the beam quality and efficiency of lasers, make the laser an even more advantageous solution to high volume or automated industrial joining.

Weld quality and consistency

Laser welding enables the quality and consistency of welding to be readily controlled and consistently maintained.  Since the laser head makes no contact with the workpiece and there is no electrode which can become worn, eroded or damaged there is no need for a tool change where the electrode needs to be reground or sharpened, as is the case with TIG.  The lack of electrode dressing in laser welding results in higher uptime and longer time between maintenance interventions.  Also, there is no risk of contamination of the weld material with Tungsten from the TIG electrode tip when striking the arc.

Lower heat input

With laser welding the heat input to the metal being welded is lower which means there is a smaller heat affected zone (HAZ) and the distortion of the assembly is vastly reduced making complex and accurate assembly more achievable, especially in an automated setting.

laser weld microTIG weld

TIG welding (left) typically exhibits higher heat input into the surrounding material – Laser welding (right) is capable of finer welds, with a much smaller heat-affected zone

In addition, the lower heat input means that a weld can be placed close to sensitive electronics or other heat-sensitive materials without risk of damage or failure.  An example of this is in cardiac pacemakers and defibrillators where the external weld seam is directly above a heat-sensitive battery and micro-electronics which cannot withstand a temperature over 80 degrees C.

Throughput – higher welding speed

Weld speeds are generally higher with laser welding, especially with modern high power continuous wave (CW) fibre lasers.  A high welding speed sometimes means that the motion system, for example the CNC system or robot contouring speed, is the limiting factor on cycle time rather than the process.

Cost per metre of weld

In processes where throughput is high it is common to find that the laser solution is more efficient and results in a lower cost per metre of weld.   Interestingly, there are processes which combine laser and arc welding to achieve deeper penetration and higher welding speeds.  These hybrid processes typically use a combination of laser welding to heat the metal efficiently to melting point and arc welding to provide deposition of droplets into the weld pool and enhanced penetration and weld strength over either process as a stand-alone procedure.

No finishing of the weld

With inert gas shielding, a laser weld in stainless steel or aluminium normally requires no post-processing (grinding or dressing) after welding, the weld finish is bright and oxide free and can be typically coated or painted without further cleaning steps.

Access difficult areas

Since the laser beam is a “line of sight” process, the laser can pass through gaps in a structure to weld areas from the rear, where it would not be possible to introduce a TIG electrode.  Using a camera to view through the laser optics, it is easy to align the beam to a precise feature and perform welds in difficult-to-reach parts of the structure.

What about gaps?

One disadvantage of laser welding is that it tends to rely on good contact and minimum gap between parts to be joined.  With either a laser process or a TIG weld, there is a need to ensure that gaps are minimised or avoided to ensure good results.  With the addition of wire feed, which adds a certain complexity to the process, it is possible to fill gaps or build up areas for additional strength.

Conclusions

For ease of automation, consistent quality and lack of post-processing there are clear advantages to using laser welding.  Where welding is to be applied manually, TIG welding has greater flexibility and lower capital cost for the equipment.

robot laser cutting system

Business Minister Anna Soubry MP opens £60 million aerospace & 3D printing research facility at the MTC

Right Honourable Anna Soubry MP Business Minister opens £60 million aerospace & 3D printing cutting edge research facilities in Manufacturing Technology Centre Coventry to maintain the UK’s world leading position in aerospace.

The state of the art robotic laser system, designed and manufactured by Cyan Tec Systems, is specifically designed to have the ultimate flexibility, meaning that industrial organisations are able to prove a production process before committing to significant financial investment. The system incorporates an ABB six axis robot, two rotary manipulators and a 20kW laser, allowing the system to handle a range of different components as well as performing the required laser processes (cutting, welding, ablating etc.).

robot laser cutting system

The minister, pictured here with the cutting edge robotic laser system, incorporating the UK’s most powerful laser, announced the launch of a new £10 million competition to find game-changing aerospace technologies, aimed at small firms.

Managing Director Tony Jones states “Cyan Tec is proud be a supplier to the Manufacturing Technology Centre, showcasing advanced manufacturing capabilities, the Cyan Tec machine breaks new ground integrating a 20kW industrial laser to drive innovation in aerospace technology.”

Cyan Tec together with industrial businesses such as Rolls Royce & the UK government are working together to keep Britain at the forefront of the global aerospace market, the UK is second only to the United States in the valuable aerospace industry with demand for aircraft at record levels, roughly 45,000 new aircraft & 40,000 helicopters required in the next 17 years, generating opportunities totalling over $5 trillion.

Cyan Tec’s CEO, Clayton Sampson, reports “It is exciting to see government ministers taking an interest in our technology & we are pleased to be part of such a valuable initiative driving world class advances in the UK’s aerospace industry.”

Cyan Tec recognises the importance of this billion pound industry to the UK economy & is proud to contribute advanced technology equipment & services to this growing sector.

Cyan Tec welcomes the joint government & industry commitment of £2.1 billion for aerospace R&D to develop new high value technologies, improve aircraft factory production & the cost competitiveness of the UK supply chain.

robot laser marking cell

New Flexible Robotic Laser Marking Cell

In response to the demand from the automotive sector, Cyan Tec Systems have produced a new flexible laser marking cell using a 6-axis robot to carry a compact laser marking head for the marking of text and 2D matrix codes onto automotive engine components.  A compact solid state laser head fitted with a miniature 2 axis galvo scanner is carried on the end of the robot arm allowing the marking field of 120 x 120 mm to be positioned anywhere within the reach of the robot, and angled to suit the plane of the component surface which is to be marked.  The laser and robot are contained within a solid walled safety enclosure which protects the operator from the robot motion and the laser during the laser marking cycle.  Interlocked safety doors allow access to the robot for programming – a monitor is positioned externally to observe the operation of the cell from outside.

robot laser marking cell

Parts are automatically loaded and unloaded via a conveyor which passes through the laser safety enclosure of the cell.  A hand-held code reader is attached to the outside of the laser cell which allows the verification of codes on the incoming and outgoing parts.  The scanner is cordless and rechargeable – the data scanned is transmitted to the master cell controller via Bluetooth.

Laser marking is the most reliable, repeatable and rapid method of putting permanent high-contrast marks on the surface of virtually any material.   Laser marks resist wear and cleaning processes which means that traceability is guaranteed for the lifetime of the components.  Cyan Tec uses the latest in fibre lasers and diode-pumped solid state lasers from the leading manufacturers, which have the characteristics to mark rapidly and with very high definition.  Almost no maintenance is necessary meaning that uptime and throughput are maximised.  Cyan Tec can work with all the major manufacturers of robots and lasers to provide a solution compatible with the norms and preferences of the customer.

Flatbed laser cutter

Laser cutting of sheet metal: High speed, minimum footprint


New from Cyan Tec Systems is a flatbed cutting system for cutting metal sheets up to 8 mm thick and with sheet sizes of up to 2 m x 1 m.  This compact system is ideal for processing sheets which can be loaded by hand onto the extending front table.  Fitted with a 3kW fibre laser, this standard machine offers excellent value and takes up minimum floor space.

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Flat Bed Laser Cutting Cell

The Hyperion-MG4-CF is the latest standard flatbed laser cutting cell from Cyan Tec.  Suited to the laser cutting of composite materials, including Carbon Fibre Reinforced Plastics (CFRP) and PEEK, the system uses a combination of galvo scanning and conventional high-speed CNC axes to cut at high speed without de-lamination of the material. Read more