Trouble cutting 16ga Aluminized

[lasermen]

We are cutting 16ga aluminized sheet and having trouble getting smooth edges and dross free. We are having to buff the edges to get them clean enough for our customer. We have a 2500watt mazak space gear. We are using O2 as our assist gas and would prefer oxygen over Nitrogen. If any one has help would appreciate it Thanks.

 

[analogkid2digitalman]

No experience (I work with CO2's to machine fused silica), but my gut tells me oxygen is a no-no, go with nitrogen. Also verify beam quality and focus. Did a quick search, many articles preferred nitrogen for aluminum, see:

http://www.lvd-group.com/strippit/articles/ta_3.html

Wheels within wheels / In a spiral array
A pattern so grand / And complex
Time after time / We lose sight of the way
Our causes can't see / Their effects.

 

[axiomatrix]

You don't want to be using oxygen assist on aluminium based materials as the oxydation is very rapid and violent, it gives you anything from a crap cut to a metal fire - not good news.

Use a high pressure inert gas, nitrogen is usually the cheapest. We use a PRC CO2 system and with a cutting feed rate of around 1500mm/min at 1600W, focus at the bottom of the plate thickness and the Nitrogen at between 8 and 10 bar through a 2mm DIA nozzle. More or less !!!

It gives us a production quality cut...

 

[chadxyz]

At my former job we cut 12ga aluminized carbon steel for customers, and it would have the same edge quality as mild steel (burr free, and oxidized). Since it is just a coating (you said aluminized right?) that is not very thick it can be cut burr free with oxygen. It may be your cut conditions, try cutting it a little slower than regular mild steel maybe like (2500 to 3000 mm/min), regular focus point, a 1.5mm orfice, 700 to 1200 watts, and set your gas pressure at between 1 to 2 bar. This should be a good starting spot. You might have to tweak things to get the proper balanced reaction going but it shouldn't be too hard. If none of this works try pulse cutting the material at 100 to 500 hz with a 50% duty cycle. A little experimetation will go a long way. Please let me know if this helps.