I have a standard 3018 pro laser/carving cnc machine. Is the laser strong enough to engrave on light metal? Do I need something else to cover the work area?
I’ve seen people discolor metal with a diode, but that’s annealing (heating it to change the color), and it’s quite slow, and likely only doable on stainless steel or titanium. You need to have very good focus, and metal conducts heat really well, so anything thick will be hard to do this with - it will just absorb the heat and dissipate it through the metal.
what would recomend?
If you want to engrave metal, the easiest way is a galvo-based fiber marking laser, but you’re looking at about $2500 minimum for a 20w unit.
The more economical option would be Cermark marking spray, but it needs a lot of heat to work well, and I honestly couldn’t say for certain if a diode laser will give good results with that. A 40w CO2 laser, like a K40, can do a decent job with Cermark or Enduramark.