Laser Welding Aluminum: Problems, Parameters, and Real-World Test Data


Laser welding aluminum often fails fast: porosity, cracks, unstable seams, and inconsistent fusion. The fix is usually not “more watts,” but controlling energy delivery, beam scanning (wobble), shielding coverage, and focus strategy as a stable process window.

This guide provides a practical, engineering-level overview of aluminum laser welding: what goes wrong, what to control, and real parameter windows based on trials using the GWEIKE M-Series.

Porosity control Wobble process window Real test parameters Setup checklist
GWEIKE Cloud product/process illustration
Key takeaways
Read this first
  • Aluminum fails from instability, not “lack of power.” Optimize for a stable melt pool window.
  • Wobble (scan width + frequency) is the fastest lever to improve consistency and reduce porosity risk.
  • Shielding + surface prep often change results more than raw wattage.

Why Aluminum Is Difficult to Laser Weld

  • High reflectivity: more energy is reflected at the start, delaying stable melt formation.
  • High thermal conductivity: heat spreads quickly, making the process swing between “lack of fusion” and “over-melting.”
  • Porosity sensitivity: trapped gas can form pores during solidification, weakening the seam.

In production, aluminum welding fails when the melt pool becomes unstable. Your goal is to keep seam formation consistent even with real-world variation (surface condition, fit-up, operator motion).


Common Problems in Aluminum Laser Welding

Problem What you see Typical cause
Porosity Pinholes / weak seam / leak paths Gas entrapment + unstable melt pool
Cracks Hairline fractures after cooling Thermal stress + rapid solidification
Shallow penetration Low strength / incomplete fusion Insufficient energy density or incorrect focus strategy
Problem
Porosity

Pinholes, leak paths, or weak seams—often showing up first on thin parts.

Root cause
Gas entrapment + unstable melt

Keyhole collapses or oscillates, so gas can’t escape before solidification.

Fix direction
Stabilize the window

Tune wobble (scan width/frequency), then validate shielding and focus reference.

Don’t chase “maximum penetration.”

For aluminum, a slightly lower but stable window usually beats a higher, unstable one.


Parameters That Actually Control Aluminum Weld Quality

For aluminum, treat these variables as a set. Changing one without the others often makes results inconsistent.

  • Laser power (W): enough to establish a stable melt pool, not simply higher.
  • Wire diameter + wire feed rate (when using wire): affects deposition stability and seam shape.
  • Beam scanning (wobble): scan width + scanning frequency influence stability and porosity tolerance.
  • PWM settings (peak power %, duty cycle, frequency): controls energy delivery behavior.
  • Shielding gas + airflow: supports oxidation control and process stability.
  • Focus strategy: aluminum often benefits from a different focus reference than steel.
Engineering rule of thumb
Optimize for a repeatable process window (stable seam) rather than chasing peak values.

Real Test Data (Aluminum) — GWEIKE M-Series

The tables below summarize aluminum parameter sets from real welding trials using the GWEIKE M-Series. Use these as starting windows and validate for your alloy, joint design, and quality target.

Test notes (from trials)
  • Shielding: Nitrogen; air flow ≥ 20 L/min.
  • Focus reference: Stainless/Carbon steel = 0; Aluminum plate = 3–5 (relative offset; validate to your optics).

Aluminum — 800W Test Window (M-Series)

Thickness (mm) Laser Power Wire Diameter Wire Feed Rate (mm/s) Peak Power (%) PWM Duty Cycle (%) PWM Frequency (Hz) Scanning Frequency (Hz) Scan Width (mm)
1 800w 1.0 -1.2 mm 13 0.55 100 1000 80 2.5
1.2 800w 1.2 mm 12 0.7 100 1000 40 3.0
1.5 800w 1.6 mm 10 0.85 100 1000 40 4.0

Aluminum — 1200W Test Window (M-Series)

Thickness (mm) Laser Power Wire Diameter Wire Feed Rate (mm/s) Peak Power (%) PWM Duty Cycle (%) PWM Frequency (Hz) Scanning Frequency (Hz) Scan Width (mm)
1 1200w 1.0 mm 15 0.5 100 1000 100 2.5
1.2 1200w 1.0 -1.2 mm 13 0.55 100 1000 80 2.5
1.5 1200w 1.2 mm 12 0.7 100 1000 40 3.0
2 1200w 1.6 mm 10 0.85 100 1000 40 4.0

Fast troubleshooting (what to adjust first)

You see…
Adjust first…
Porosity / pinholes
Scan width + scanning frequency → then check shielding coverage & surface prep.
Lack of fusion
Focus strategy → then peak power / wire feed balance.
Over-melt / excessive bead
Reduce energy density (peak/duty), re-check wire feed, keep travel consistency.
How to adjust when results are unstable
  • Porosity / instability → tune scan width + scanning frequency first.
  • Inconsistent fusion → validate focus strategy, then adjust PWM / peak power.
  • Still unstable → re-check surface prep and shielding coverage.
Want a parameter window for your aluminum part?

Send your alloy grade, thickness, joint design, and quality standard. We’ll recommend a starting window based on your target.

Explore GWEIKE M-Series

Why Wobble (Beam Scanning) Helps Aluminum

Aluminum is sensitive to melt pool instability. Beam scanning (“wobble”) often improves real-world results by:

  • Stabilizing melt pool behavior across small fit-up changes
  • Improving tolerance to gas entrapment (lower porosity risk)
  • Making seam formation more consistent and repeatable

In many applications, wobble is less about “more penetration” and more about higher consistency.


6) Practical Setup Tips (What Actually Changes Results)

Pre-weld checklist
  • Remove oil/moisture; avoid welding wet aluminum.
  • Confirm stable shielding coverage (nozzle distance & angle).
  • Lock joint fit-up (gap, clamping) before parameter tuning.
During welding
  • Keep travel speed consistent (avoid stops/hesitation).
  • Start with the test window; adjust wobble before power.
  • Record settings per thickness for repeatability.
Reminder
Trials used nitrogen shielding with air flow ≥ 20 L/min and a relative focus offset reference (aluminum = 3–5).

FAQ: Laser Welding Aluminum

1) Can you laser weld aluminum without porosity?

Yes. Porosity can be reduced by stabilizing the melt pool and improving gas escape. In practice, wobble (beam scanning), correct shielding coverage, and clean surfaces are the biggest levers.

2) What shielding gas is used for aluminum laser welding?

Shielding choice depends on oxidation requirements and your process. In the aluminum tests referenced here, nitrogen was used with air flow ≥ 20 L/min. Always validate shielding on your alloy and seam requirement.

3) Do I need wobble (beam scanning) for aluminum?

It’s not mandatory, but it often makes aluminum welding far more stable. Wobble can widen the acceptable process window and improve consistency when fit-up and surfaces vary.

4) What thickness range is practical for compact/handheld laser welding systems?

It depends on alloy and joint design. Many real applications focus on thin to medium thickness parts where consistency matters. Use the parameter windows above as starting points, then validate on your geometry and quality standard.

5) What is the most important setup step before adjusting parameters?

Surface preparation and shielding coverage. Dirty or wet aluminum can create defects that no parameter tweak fully fixes. Stabilize cleanliness, gas coverage, and focus reference first, then optimize scan and PWM settings.


Related Reading

Product reference
If you need aluminum welding plus cutting/cleaning/marking in one workstation, see GWEIKE M-Series.
ブログに戻る