Hi all,
we're trying to cut shapes out of 1 mm thick silver sheet. The machine we're using is a brand new Beamer, middle power range, model 50 I think. The machine is intended primarily for laser marking and it uses high speed galvos for beam steering. The engraving performance is acceptable but the cutting or blanking out is still not working.
We're testing the cut trhrough performance by cutting out a 1/2" square.
It is supposed to cut clean trhough a .040" thick silver sheet, but it requires about 25 passes around in order to cut through, and there is a small amount of recast on the underside edge. It will cut through .030" thick with 15 passes. The metal workpiece sheet (skeleton) gets extremely hot. It was supposed to go to 2MM thickness.
The sides of the cut are smooth, but the recast or slag is disappointing because it will require some post production cleanup.
The control software and machine control is custom. There is no gcode, you can import vector graphics bu the scaling appears to be off. From what I know, the manufacturer says the laser has to cut a series of tiny circles as it moves along the cutting path.
Would anyone have any experience with this machine or in general cutting silver, gold, copper and brass with a pulsed fiber laser? Please note that these materials can't be cut with CO2 lasers, I think because of the heat conduction of these metals. These materials require extremely short duration, high energy laser pulses to ablate, or phase change the base metal into plasma, in so brief a period of time that the metal never has enough time to get hot.
We were under the impression that this machine would cut the blanks out in one pass. I'm wondering if the laser source is correct for our application. Perhaps our problem is caused by the settings we've entered. We have control over these 3 variables, cutting speed, power, and frequency.
My thinking is that if we were to increase the power setting but reduce the duty cycle, we'd get better performance because we'd be ablating more, thereby changing the material state to plasma, and heating less, as opposed to a longer duration and lower power laser pulse heating up the part. Less recast too perhaps.
Would anyone care to comment?