Metal processing

Metal draws heat away fast, so longer pulses melt the edge and leave burrs and a wide heat-affected zone. Femtosecond laser pulses remove material before the heat spreads: stents and thin parts are cut with smooth, burr-free edges, surfaces are textured to change their properties, and metals are marked black or in color without inks.

Material processing
Material processing Glass Metal Polymer Other materials
Metal

Metal surface texturing

Femtosecond pulses can functionalize a metal surface. Near the ablation threshold the beam writes laser-induced periodic surface structures (LIPSS), a fine regular ripple that changes the properties of the surface itself rather than its shape. Light absorption rises, which is what makes black marking possible; wetting behavior shifts; tribological performance improves; and bacterial adhesion drops.

FemtoLux is used for this work. It textures master molds, aluminum among them, with detailed surface geometry. It also produces antibacterial surfaces: tuning the pulse energy adds nano-features on top of a coarser pattern, and the resulting hierarchical texture markedly reduces bacterial adhesion.

The same laser can also remove a texture. Working in GHz burst mode on stainless steel, 100 pulses per burst at a burst fluence of 0.15 J/cm² erased existing LIPSS and cut the average roughness Ra from 73 nm to 41 nm. Texturing and polishing therefore run on one system, without changing tools between them.

Nitinol textured with a square grid, each cell filled with LIPSS ripples.

Nitinol textured with a square grid, each cell filled with LIPSS ripples.

Courtesy of UNIMORE.

Manufacturing examples

Stainless steel textured with a triangular grid; the inset shows the LIPSS filling one cell.

Stainless steel textured with a triangular grid; the inset shows the LIPSS filling one cell.

Courtesy of UNIMORE.

Textured aluminum molds: 3D surface maps of the dimple array and the fine ridge texture, with the finished mold plates below.

Textured aluminum molds: 3D surface maps of the dimple array and the fine ridge texture, with the finished mold plates below.

Courtesy of FTMC.

Publications

Surface Structuring FemtoLux
Ultrashort Pulse Bursts for Surface Laser Polishing
S. Steponavičiūtė, P. Gečys, G. Račiukaitis, M. Gedvilas, and A. Žemaitis, in Optics, Photonics and Lasers OPAL’ 2024 Conference Proceedings, S. Y. Yurish, ed. (IFSA Publishing, 2024), pp. 44.

Recommended products

FemtoLux
Industrial Femtosecond Lasers
  • 50 W / >300 µJ at 1030 nm
  • 20 W / >50 µJ at 515 nm
  • 10 W / >25 µJ at 343 nm
  • < 400 fs – 1 ps
  • Single shot to 4 MHz (AOM controlled)
  • MHz, GHz, MHz+GHz burst modes

Similar applications

Optical photograph of laser milled aluminium Fresnel lens mould, diameter 35 mm.
Metal milling in MHz burst mode

Femtosecond milling of metal gives high quality but limited throughput, because the most efficient fluence is hard to reach at high average power. MHz burst mode splits one high-energy pulse into sub-pulses, which restores the optimum fluence and raises removal efficiency by 18% on aluminum, 44.5% on copper and 37% on steel.
Perforated disc cut in stainless steel.
Cutting of various metals

Stainless steel, copper, tantalum and Kovar have all been cut with the same femtosecond laser, in foils from 50 to 125 µm thick. Only the pulse energy and scan parameters change between them, and the cut edges stay smooth and burr-free with a minimal heat-affected zone.
Black-marked QR codes and logos on medical tweezers.
Black/color marking of metals

Femtosecond pulses roughen the metal surface until it absorbs almost all incident light, which leaves a black mark of high contrast and strong resistance to environmental effects. A gentler thermal load does the opposite job: it grows a thin oxide layer, and the layer thickness sets the color, with no inks or chemical additives.
Nitinol demo part cut with two strut patterns, with lettering marked on the solid band between them.
Nitinol stent cutting

Femtosecond lasers are the best choice for cutting nitinol stents. Their ultra-short pulses cut with very high precision, so the edges come out smooth, with almost no burr and only a small heat-affected zone. That matters for stents, whose fine geometry and exact dimensions have to work inside the body.
All applications