When metal is heated, its color is altered due to an annealing effect. This effect is created because of structural changes in the outer metal layer. The laser allows the creation of areas and structures / textures on the workpiece surface in different colors without the use of additives.
The table on the right shows examples of different annealing colors of unalloyed tool steel.
| Annealing colors for unalloyed tool steel |
Annealing temp. °C | |
|---|---|---|
| Whitish yellow |  |
200 |
| Straw yellow |  |
220 |
| Golden yellow |  |
230 |
| Yellowish brown |  |
240 |
| Brownish red |  |
250 |
| Red |  |
260 |
| Purple red |  |
270 |
| Violet |  |
280 |
| Dark blue |  |
290 |
| Cornflower blue |  |
300 |
| Light blue |  |
320 |
| Bluish gray |  |
340 |
| Grey |  |
660 |
Laser marking center SHARK ®
Strong performance, plenty of space and the highest precision for fast marking.
Annealing marking with the laser
The highly exact mechanical construction of ACSYS laser systems and the laser focusing allow the positioning of the colors within the µm-range. The marked workpieces are temperature-stable up to the annealing temperature.
For further examples please see applications under Metals.
