Laser Welding

Key Characteristics of the Laser Welding Process

Laser welding is a non-contact joining process that requires access to the weld zone from only one side of the parts being welded.

• Supports many joint geometries
• Requires close fit-up at joint interfaces
• Tooling quality is a critical success factor

Types of Laser Welds

Three primary types of welds can be achieved with a laser welder, depending on power density and process parameters:

Conduction Welding

• Performed at low power
• Produces wide, shallow weld nuggets
• Minimal penetration

Transition / Keyhole Welding

• Uses medium power density
• Produces a deeper weld nugget
• Typical width-to-depth ratio of approximately 1:1

Penetration (Full Keyhole) Welding

• Results from direct power delivery into the material via a keyhole
• Produces deep, narrow welds
• Typical width-to-depth ratio between 3:1 and 10:1

What is Laser Spot Welding?

Laser spot welding uses a laser welder to create a single weld spot that joins metals together. Laser welders deliver a precise pulse of light with accurately controlled power, energy, and duration, enabling highly repeatable results.

How Laser Spot Welding Works

When the laser pulse is focused into a small spot – typically adjustable from approximately 0.02 to 1.0 mm (0.001”–0.040”) in diameter – the resulting power density causes rapid melting of the material.

• High power density promotes efficient laser absorption
• The keyhole effect enables deeper penetration
• Molten metal resolidifies as the pulse ends

The entire spot welding process occurs in just a few milliseconds.

What is Laser Seam Welding?

In laser seam welding, the part being welded is moved or rotated under the laser focus head, allowing individual laser welds to overlap or, in the case of CW fiber lasers, enabling continuous penetration.

Key Parameters in Laser Seam Welding

Pulsed Laser Seam Welding

• Pulse repetition rate (Hz)
• Linear travel rate or welding speed
• Focused spot diameter

Continuous Wave (CW) Fiber Laser Seam Welding

• Laser power
• Spot size
• Focus position

For both approaches, these parameters are precisely controlled to achieve the desired weld characteristics, whether for mechanical strength or hermetic sealing.

Materials Suitable for Laser Welding

Pulsed Nd:YAG, pulsed fiber, and CW fiber laser welders can join a wide range of materials, including:

• Mild steel
• Stainless steel
• Nickel and nickel alloys
• Titanium
• Aluminum

• Copper and copper alloys

Dissimilar metal welding is also possible between select material combinations.