Materials Suitable for Laser Welding

Laser welding is compatible with a wide range of industrial metals, including stainless steel, carbon steel, aluminum, copper, brass and select coated metals.(industrial fiber laser welding systems) Because of the extremely concentrated heat input and excellent controllability of a fiber laser beam, many materials that are challenging for TIG/MIG become easier and more consistent to weld using laser technology.

This guide explains how different metals respond to laser welding—what materials are most suitable, how heat input affects weld quality, which parameters influence penetration and stability, and what thickness ranges deliver the best results in real production environments.

Why Material Properties Matter in Laser Welding

The interaction between the laser beam and metal depends on basic laser welding principles:

• Absorptivity at the laser wavelength (1070–1080 nm)
• Thermal conductivity (how fast heat spreads)
• Reflectivity (especially for aluminum and copper)
• Melting temperature
• Surface condition (oxide, coatings, oil)

Stainless steel, for example, has good absorption and moderate thermal conductivity, making it one of the easiest materials to laser weld. Aluminum has high reflectivity and high thermal conductivity, making it more demanding.

Stainless Steel — The Most Laser-Friendly Material

Stainless steel is considered the ideal material for laser welding due to its:

• High absorption rate for near-IR lasers
• Low thermal conductivity (heat stays localized)
• Stable molten pool and smooth flow
• Consistent penetration and excellent surface finish

Suitable Grades

• 304 / 304L
• 316 / 316L
• 430 (ferritic)
• Duplex grades (with optimized shielding)

Ideal Thickness Range

Handheld and gantry fiber lasers perform best with 0.5–4.0 mm stainless steel:

• 0.5–1.0 mm → conduction or shallow keyhole
• 1.2–3.0 mm → stable penetration with 800–1200 W systems
• 3.0–4.0 mm → requires higher peak power and controlled wobble

Parameters (from real-world GWK data)

• 0.8 mm: 30–38% peak power
• 1.2 mm: 40–45% peak power
• 2.0 mm: 45–55% peak power
See recommended machines for stainless-steel welding

Industrial Applications

• Kitchen equipment
• Stainless cabinets and enclosures
• Food processing machinery
• Medical equipment

Carbon Steel — Deep Penetration, High Strength

Carbon steel also welds extremely well with fiber lasers, achieving deep penetration and strong welds. However, carbon steel can oxidize and darken if shielding gas is insufficient.

Suitable Grades

• Mild steel (Q235, S235)
• High-strength low alloy steel (HSLA)
• Galvanized steel (with specific techniques)
M-Series carbon-steel welding capability

Thickness Range

Carbon steel up to 4 mm can be welded with 800–1500 W handheld systems. For CO₂-based techniques, much higher power would be required.

Parameter Behavior

• Absorbs laser energy efficiently
• High penetration under keyhole mode
• Spatter more likely without proper gas flow

Key Tips

• Ensure 15–20 L/min shielding gas
• Use moderate wobble (1–3 mm)
• Clean zinc from galvanized steel before welding

Aluminum — Weldable but Requires Precision

Aluminum is highly reflective and conductive, making it one of the more challenging materials for laser welding. However, with proper settings, fiber lasers can produce high-quality aluminum welds with minimal porosity.

Suitable Grades

• 1xxx and 3xxx series
• 5xxx and 6xxx series (automotive, structural)

Thickness Range

Fiber laser welding performs best with 1.0–3.0 mm aluminum sheets.

Key Characteristics

• High reflectivity at 1070 nm
• High thermal conductivity → heat dissipates quickly
• Oxide layer melts at higher temperature than aluminum base

Best Practices

• Use higher peak power (e.g. 60–85%)
• Use positive focus (+2 to +5 mm)
• Clean oxide layer immediately before welding
• Use high gas flow to minimize porosity
• Wobble width 2–4 mm improves stability
laser cleaning of aluminum oxide layer

Copper & Copper Alloys — High Reflectivity Materials

Copper and brass reflect most infrared laser energy. However, modern high-power fiber lasers can weld these materials effectively with the right settings. High-power fiber laser welding systems

Material Behavior

• High reflectivity → requires higher peak power
• High thermal conductivity → heat spreads rapidly
• Excellent electrical/thermal conductivity after welding

Applications

• EV battery components
• Busbars
• Heat exchangers
• Electronics

Titanium — Clean, High-Performance Welding

Titanium welds exceptionally well with laser because it forms a stable keyhole and strong, corrosion-resistant welds. However, its molten surface is extremely reactive and requires perfect shielding.

Best Practices

• Use high-purity Argon shielding
• Longer post-flow time
• Stable fixtures to prevent contamination

Coated and Painted Metals

Laser welding can work on coated metals, but there are important constraints:

Galvanized Steel

Zinc vaporization can cause porosity. Solutions include:

• Cleaning zinc around the seam
• Using larger wobble width
• Lowering focus to stabilize keyhole

Painted or Powder-Coated Metals

• Coating must be removed before welding
• Laser cleaning module is useful for preparation

Materials Not Recommended for Laser Welding

While laser welding works well on many metals, certain materials are not ideal:

• Very thick steel (>8–10 mm) using handheld systems
• Metals with heavy surface contaminants
• Highly reflective alloys without sufficient power
• Metals with foamed or porous structure

For these cases, hybrid welding or mechanical joining processes may offer better results.