fdm printers CAN NOT print metal.
Lets get that straight.

For $100,000 you can buy a system that uses metal powder bound by a small amount of plastic to print an object.
That object is - carefully - transferred to a washer that removes most of the binding plastic. This is then - even more carefully - transferred to an oven that cooks it to around 1800c and effectively sinters the print into solid metal. The washer alone is around $30,000 !
I don't know why.

The system was developed by Markforge and stolen (an opinion) by desktop metal.
Law suits are in progress.
Essentially the brother of the desktop metal ceo was working at markforge when they developed the technology that desktop metal subsequently claimed as their own. The two systems are virtually identical. Draw your own conclusions.

There are also systems in place that use metal powders that have resins jetted directly onto the metal layer and the part is then washed and sintered in a similiar manner.
Had a virtual reality tour around a factory that uses this method at tct last year. Was pretty impressive.

What you can get, are plastic filaments that Use very fine metal powders as a colourant.
They are visually effective. But generally the more foreign bodies you insert into plastic - the weaker it gets.


Full on metal printers start around the ?150,000 mark. Most use powdered metals and fuse layers with lasers or electron beams. Other systems exist that can bolt onto cnc machines and robotic arms that use a plasma arc and nitrogen flow and 'blow' the metal powder onto an object.
They cost so much because you have to totally remove oxygen out of the equation, otherwise your metal burns rather than melts.
Also the very fine metal powders involved have to be contained - you do NOT want to breathe that stuff in !
So metal printers come with sealed environments and industrial level filtration systems.

Metal printing is fascinating.
But not affordable yet.
That said - the automotive and aerospace industry use a lot of hi-spec custom parts and that's where 99% of the market currently is.

There are some really strong materials around - but strength will cost.