What would the van der Waals parameters look like for gaseous metals? So basically I'm trying to do some calculations on laser based machining, and it involved vaporizing a small mass from a target metal workpiece. I was assuming that a certain m mass of the metal vaporizes nearly instantaneously, and the resulting vapor expands from that initial volume.
I was using the van der Waals corrected gas equation, and wasn't sure how to quantify a and b for gaseous metals (take Al for example). I tried searching online, but couldn't find any values for gaseous metals.
Any help or resources I could refer to would be appreciated.
Aside from the metal vapor oxidizing, the pressure of gas over your weld is unlikely to be much different from one atmosphere whereas the critical pressure of almost everything is 10 atmospheres or (often a lot) more.  Generally gases become non-ideal when the pressure is a large fraction of the critical one; we are well below pressures where that occurs.  So the Ideal Gas Law works -- until the metal vapor oxidizes.