Marking Anodized Aluminum

[Tuxifix]

Hi fellow laser enthusiasts,

I already asked the question in my 'Welcome' thread, but I guess it is better to have a dedicated thread for this.

Does anyone have experience with laser-marking or -engraving black anodized aluminum, i.e. removing the anodized layer to expose the bare aluminum? I know this is possible with some CO2 and of course Q-switched lasers, but is it also possible with diodes, e.g. with a NUBM44 or 405nm diode?

Another note: For me, this is supposed to be a DIY project. I work with commercial lasers professionally, but I would like to learn how to build such a laser myself (if there exists a diode for it, anyway). So I would be glad to get some information about the type of diodes that might be suitable (again, if existing ), not just ready-to-use modules.

Best regards,
Tuxifix

 

[Encap]

Google "laser engraving anodized aluminum" there are thousands of links on the subject including videos

See: https://howtolaser.com/blog/laser-engraving-anodized-aluminium-the-right-way/

 

[Tuxifix]

Google "laser engraving anodized aluminum" there are thousands of links on the subject including videos

There certainly are. But unfortunately not a lot with diodes, and if so, no type of diode is mentioned.

See: https://howtolaser.com/blog/laser-engraving-anodized-aluminium-the-right-way/

This is done with a 90W CO2 laser, which is not what I had in mind. But thanks for the link, anyway.

 

[logsquared]

You want to ask on the photonlexicon board. There are a few engraver guys on that forum.

 

[Tuxifix]

You want to ask on the photonlexicon board. There are a few engraver guys on that forum.

Well, this is embarrassing. There is the exact same question on that board. I can not imagine how I missed that.
Thanks a lot for the hint.
Apparently, 500mW 405nm or 1W 450nm with focal spots of 0.1mm are sufficient to remove the oxide coating.

Best regards,
Tuxifix

 

[paul1598419]

You'll find the power density of your beam is more easily achieved with a single mode 405nm diode. Try either the S06J or the BDR-209. The 1 watt 450nm diodes as well as the 445nm diodes are all multi mode and that makes getting the power density increase more difficult, but not impossible.

 

[Tuxifix]

You'll find the power density of your beam is more easily achieved with a single mode 405nm diode. Try either the S06J or the BDR-209. The 1 watt 450nm diodes as well as the 445nm diodes are all multi mode and that makes getting the power density increase more difficult, but not impossible.

Thanks for the recommendation! Unfortunately, I already just ordered a >4W NUBM08 for 30€, and see how far I can go with it. I guess even though the multimode diodes have a lower power density they are less susceptible to non-ideal focussing.

 

[paul1598419]

What do you mean by less than ideal? A single mode diode is far easier to focus to the small size you were looking for. A BDR-209 laser diode can be driven to 900+ mW and at a higher power density than your NUBM08 can. They are also less than 30 Euros. Drive one at 550 mA and heat sink it well. A good actively cooled lab host would work best for this.

 

[Tuxifix]

What do you mean by less than ideal? A single mode diode is far easier to focus to the small size you were looking for. A BDR-209 laser diode can be driven to 900+ mW and at a higher power density than your NUBM08 can. They are also less than 30 Euros. Drive one at 550 mA and heat sink it well. A good actively cooled lab host would work best for this.

With less ideal focussing I mean aberations. Too bad, I already ordered the NUBM08. I will first see if this works for me, otherwise I might give the BDR-209 a try.