Why maximum weldable thickness varies by material
When working with laser welding, equipment power is only part of the equation. The maximum thickness achievable in each material depends fundamentally on two intrinsic physical properties: heat dissipation capacity and reflectivity.
1. Heat dissipation capacity (thermal conductivity)
Each material conducts and dissipates heat differently. Materials with high thermal conductivity, such as copper or aluminum, evacuate heat from the fusion point very rapidly to the rest of the part. This requires higher energy density or greater power to maintain the molten pool long enough, reducing the effective thickness achievable.
Stainless steel, by contrast, has considerably lower thermal conductivity: it retains heat in the welding zone, facilitating deep fusion with the same power.
2. Material reflectivity
The wavelength of the fiber laser in the Quantum range is 1080 nm. At this wavelength, materials such as copper and aluminum exhibit very high reflectivity: a significant fraction of the beam energy is reflected rather than absorbed. Stainless steel and carbon steel absorb the laser with much greater efficiency, allowing more useful energy to be transferred to the material.
How this translates to the Quantum range
This combination of factors explains why, for example, in the Quantum Q5A (1500 W) stainless steel can be welded up to 5 mm, aluminum up to 4 mm and copper only up to 2 mm — at equal power, each material responds differently.
The Quantum Q9A (2200 W), with its higher power and exclusive TURBO mode, expands these ranges: stainless steel up to 7 mm, aluminum up to 5 mm and copper up to 2 mm.
Knowing these properties allows you to select the appropriate Quantum model for each application and configure optimal welding parameters.