Laser welding: areas of application, modes of operation & devices

Laser Welding: The Advantages at a Glance

Laser welding, often referred to as laser beam welding, describes a welding process that uses laser energy to create weld joints, primarily between metallic workpieces. Compared to other welding techniques, laser beam welding has numerous advantages:

Precise energy input even for the finest structures
Very small heat-affected zones
High mechanical strength of the seam
Contactless laser welding without exerting force on the workpiece
Good process control for consistent manufacturing quality
Good accessibility
Suitable for welding complex materials, such as aluminum or titanium

Whether laser beam welding, additive manufacturing or laser hardening – ALPHA LASER offers comprehensive laser systems for various applications and industries.

Suitable products for laser welding

ALM Mobile welding laser with short set-up times and great flexibility at work. Open product	AL-CROSS Series Mobile fiber laser for precision laser welding with plenty of storage space and a well thought-out transport concept. Open product	ALFlak Max Mobile laser welding device with extra long reach for welding on large components. Open product
ALFlak \| ALFlak Fiber Laser welding system for programmed or manual welding. Available as Nd:YAG or fiber laser. Open product	AL-Serie Lamp-pumped laser source with flexible and extensive equipment. Available from 120-500 W. Open product	AL-IN The AL-IN is a very flexible and robust laser system for welding small and large components. Open product
AL-TW Stable working table with integrated fiber laser. Available with 300, 450, 600 or 900 Watts. Welding in pulsed mode or in continuous mode is possible. Open product	ALW / ALW Fiber Laser welding in the manufacturing environment without additional safety measures. Choice of laser source and laser power. For workpieces up to 400 kg. Open product	ALV / ALV Fiber Compact laser welding system that can also be placed in a small workshop. And yet everything is included: laser, travel system, extraction and laser safety. For workpieces up to 50 kg. Open product
AL-Q Open product	VLO 60 Compact desktop laser device for manual welding. Open product	ALO If you need to weld long or bulky parts quickly, manually and flexibly, if you are looking for a simple load and want to work in the shielded laser safety area, then the ALO is the ideal device. Open product
AL-SWS Interesting and flexible system for the production of sensors. Open product

Laser welding: functional principle & areas of application

In laser welding, welding is carried out using laser energy. The laser beam is optically focused so that a high energy input melts a very small area. During laser welding, the weld pool is protected from oxidation by shielding gas, usually argon. In the weld pool, the workpieces and the filler metal join to form a weld seam. By focusing the laser beam, the heat input is limited to a small part of the workpiece, which means that the weld seam cools down quickly - a result of the high temperature gradient between the welded area and the entire workpiece.

Due to the precise processing with very low distortion and the high welding speed that can be achieved with the laser systems, laser beam welding is used in numerous areas of application, including

Automotive industry
mechanical engineering
precision engineering
shipbuilding
toolmaking
Medical and dental technology
Jewelry industry
Sheet metal processing
steel construction
Aerospace industry
Casting repair
Sensor production
Repair welding

Laser welding: these types are available

Different laser welding techniques are used depending on the area of application. These differ primarily in the shape of the resulting weld seam by setting the welding parameters accordingly. The following laser welding processes exist:

Deep penetration welding: In deep penetration welding, the laser intensity is particularly high so that the vaporization effect occurs and metal plasma is formed. Deep penetration welding is the most common variant of laser welding.
Micro welding: Micro welding refers to welding processes in which components of very small sizes are welded together. One form of micro-welding is spot welding; resistance brazing and enameled wire welding also fall into this category.
Spot welding: Small welds with a diameter of less than 0.1 millimeters are produced with a low heat load during spot welding. This creates a weld seam consisting of many small spot welds. This process is suitable for small geometries.
Seam welding: Seam welding is a welding process in which the laser source continuously produces a weld seam. This ensures a high welding speed, which is required for joint welding in overlap or butt welding, among other things.
Heat conduction welding: Heat conduction welding offers a very flat weld. As the laser intensity remains below the threshold, there is no deep penetration welding.
Powder deposition welding: Laser deposition welding is a type of welding in which metal powder is welded onto a component using laser energy. A smooth layer is created with little heat input. It enables different layer thicknesses and 3D volumes and is used in particular in the automotive industry, the energy sector and toolmaking.
Scanner welding: With scanner welding, the laser beam is positioned without having to align the workpiece or the processing head - the laser beam is aligned using a rotating mirror.

Precise & fast laser beam welding with laser systems from ALPHA LASER

ALPHA LASER has set itself the task of making the laser welding process ever more precise, application-oriented and faster. With ALPHA LASER laser systems, numerous materials, including metallic materials with high thermal conductivity or high melting temperatures, can be welded in no time at all.

These are the features that make ALPHA LASER laser welding systems stand out:

high laser energy
ease of use
Flexible adjustment of welding parameters, including laser focus, workpiece thickness & laser pulse
pinpoint energy input thanks to precise fiber lasers and Nd:YAG lasers
low heat input
No material distortion
clean & precise result as well as slim seam geometry on butt seams, overlap seams or fillet welds at an appropriate welding speed
can also be used for powder deposition welding, depending on the laser system
Maximum flexibility thanks to automated, semi-automated or manual laser welding
depending on the laser welding machine, mobile laser welding is also possible
Pulse welding & CW welding
Video sequences

Flexible laser welding with manual, automated & semi-automated lasers

ALPHA LASER Lasermaschinen schweißen mit und ohne Zusatzwerkstoff bzw. Drahtförderung automatisiert, halbautomatisiert und manuell.

Automated laser welding: Automated laser welding systems use our WINLaserNC software, with which the welding process (paths and laser parameters) is programmed or entered. The laser welding machine feeds the filler material using an automatic wire feed system. This procedure is ideal for welding large areas or frequently recurring components. The process is controlled either via the binoculars or via our HDMI camera with monitor.
Semi-automated laser welding: With semi-automated laser welding, the operator has the option of moving one or more axes automatically at a preset speed, so that he only has to make curves or small corrections with the joystick of the laser welding machine.
Manual laser welding: Our manual welding lasers provide you with maximum flexibility for laser welding. In manual laser welding, the filler material is fed in by hand and the welding process is monitored via the binoculars.

Laser hardening

Additive Manufacturing

Powder deposit welding

Laser welding: The most frequently asked questions

What are the advantages of laser welding?

Preheating of the material is usually not necessary: ??With laser welding, energy is very selectively introduced into the workpiece, which significantly reduces the heat impact.
Significantly low thermal distortion
high mechanical strength of the weld seam
The material deposition can be flexibly influenced and controlled by the choice of the welding wire

How does laser welding work?

With laser welding, light is focused on a 0.2 to 2 mm small spot via the focusing optics. The energy input at the focal spot is very high, which causes the material surface to melt quickly. Depending on the welding requirements, the joint can be made with or without different filler metals (wire). At the same time, the weld seams are cooled again at high speed due to the temperature difference in the workpiece. As a result, the thermal distortion of the material is very low.

What is the difference between CW laser welding and pulsed laser welding?

When welding in CW mode, a continuous melt is the result. When welding in pulsed mode the melt cools during the pulse pauses, which results in a lower welding depth, less distortion on thin components and a lower energy input into the material.

CW laser welding or “CW deep welding”, on the other hand, achieves large welding depths through high energy densities (high average power with a small focus diameter). The “CW thermal conduction welding” process is also used for build-up and joint welding of crack-prone base materials, which enables a very homogeneous weld metal without micro-cracks, depending on the joined material.

Which materials can be welded with ALPHA LASER laser systems?

(Almost) all metals and their alloys such as aluminum, titanium, steels and stainless steel, cast iron, gold, silver and platinum.

What prior knowledge do I need to use laser welding?

Almost none. However, manual dexterity is not a bad thing. Material knowledge about the behavior of metals is an advantage, but is also learned while working with the laser. ALPHA LASER offers welding training with wire knowledge. There is also follow-up training or training for new employees. The initial training usually takes place on site at the customer's premises. For follow-up training, you choose whether you prefer to do this at your company or in the ALPHA LASER training rooms.

Is laser welding dangerous?

ALPHA LASER has developed a comprehensive safety concept in cooperation with institutions and experts and trains laser users accordingly. It is imperative to ensure correct eye protection and to protect the skin against UV radiation. We offer a comprehensive range of safety accessories and appropriate advice.

ALPHA LASER laser systems meet the requirements of Performance Level d. At ALPHA LASER, you can train to become a laser safety officer.

Is my application suitable for laser welding?

The application engineers at ALPHA LASER will support you in process development. We create sample welds and advise you on selecting the right laser parameters and suitable filler material.

What can be saved by laser welding?

Laser welding saves time and material. Defects in tools are welded on precisely and reworked with little effort. This means that the tool can continue to be used and there is no need to purchase a new one. In general, the service life of molds and tools can be extended, which contributes significantly to sustainability. Time is saved as the laser welding process applies heat locally to the material, thus avoiding distortion. It is usually not necessary to preheat the material.

What needs to be considered for a LASER workstation?

First of all, laser safety. Either through a closed system or, in the case of open laser welding machines, by complying with the legal regulations. We will support you here with advice. Ergonomics is another important point. This is where ALPHA LASER laser systems score with their flexible settings and appropriate design. Good lighting is also important.

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