Both bare and anodized aluminum can be engraved with fiber laser, though it can be more challenging to engrave bare aluminum with a CO2 laser than anodized aluminum.
The best system for engraving bare aluminum sheet metals is a fiber laser. For CO2 lasers, the operator must spray a special paste as a pretreatment for the metal. Then, the CO2 laser produces heat that glues the chiseling agent to the bare aluminum. The process takes time and calls for high power configuration. If not done at a low speed and with high power settings, the marks can easily wipe off, thus requiring a repeat job. Because of these factors, it can cost more to have a CO2 laser perform the same process. However, no material is removed with a CO2 laser marking, so the marking doesn’t affect the material’s integrity.
Anodized aluminum, however, can be engraved with equal ease using either type of laser. Anodized aluminum is simply aluminum with an oxide layer coating. This coating makes the material more corrosion and UV resistant while offering better lubrication and low-cost maintenance. This type of aluminum is easily laser engraved, whether using fiber or CO2 laser engraving. Because of this, it’s easier to create a permanent mark at low power and cost. However, the grade of anodized aluminum can affect the ease with which it is engraved; while Type I and II anodized aluminum has thinner layers that are easier to engrave on, Type III sheets require a higher power output to cut through the anodized coating.
