Laser engraving metal

[andy_con]

Has anyone done any research on what wavelength and power is needed/best to mark metal? Mainly ally

[danielbriggs]

Anodised (black) aluminium works really well to engrave onto with a cheap CO2 laser engraver (10-20W).

[andy_con]

Um shiny silver metal and I was hoping for something diode based

[NobleGas]

Looking at the reflectivity vs wavelength curves, 808nm would be your best bet as Al has a dip right around that wavelength (it's still about 80% though, so watch out for the reflections)

[andy_con]

Um ok might see what diodes I can find and have a play. I'll be getting safety glasses to match

[VDX]

... you can mark metal with painting it black and removing the colour with a 2W@445nm-diode - the plasma and chemistry while evaporating the paint will oxidize and 'etch' the surface.

Dark anodized aluminium ist easy to mark with this diodes too.

For shiny metal and direct diode ( I'm using fibercoupled 975nm-diodes) you'll need more than 15Watts focussed on a spot of 0.1mm or finer -- with a DC fiberlaser @1070nm on a spot of 0.02mm it's starting to engrave at around 5Watts and up ... pulsed types can be of 2W averaged, as the pulse peak power is much higher than with DC types ...

Viktor

[andy_con]

let me do some ebay searching

[andy_con]

found this on ebay

http://www.ebay.com/itm/975nm-8W-Fib...item20f3805f9d

or 40w of 808

http://www.ebay.com/itm/JDSU-Coheren...item21030ad077

[VDX]

... the diode in the first link is good for engraving, as it's emitting out through a 0.1mm glass fiber, what can be refocussed to a spot of 0.2 to 0.1mm with a single lens.

The second one is a diode bar with 19 single emitters in a row, what will give a line instead of a spot ...

Viktor

[andy_con]

good enough for engraving bare ally?