I got two filaments with our first order, the first was copper and now that the roll is almost used up I’m trying 1074 steel. first impressions:
1: The filament is way more brittle. With copper I just have to be careful about sudden bends and curves. With the steel the snapping is just silly. making me do equally silly things like this:
in order to make it easy for the spool to unroll… don’t ask me how long this task took me or the other things I tried first…
In the end, filament still broke during my first few tries, and I found it easiest to just break off small lengths and let them hang loose from the extruder. Of course this means I can only make small parts, but it’s fine for now.
2: It requires much slower printing speeds than copper. random uneducated guess: it has a higher proportion of PLA than copper to get it to acceptable bending (though I have no clue why the copper PLA would bend more easily anyway) which means that there’s more PLA to stay melted/flow/be impacted by the metal’s high thermal mass. Regardless of the reason, these are what a couple of my first green parts are compared to copper:
That’s at 60-70 percent of the speed, too. I will try printing very slow and maybe a lower temperature and see how that gets me.
3: Sintering is going to be harder, too, for a couple of reasons. A big one is that iron is just more easily oxidized than copper, and then that oxide layer isn’t as protective. And it’s just plain carbon steel, and the amount of carbon is pretty important to what kind of steel it is. And my method of reducing oxygen is to throw it in with a bunch of carbon…
For my first go I got really lazy and debound it under copper conditions because I was doing those at the same time, so 100F peak temperature less. I then sintered at a more direct profile than recommended, so first just 5 hour ramp to 1100 C and then two hours to the peak sintering temperature, the same 3 hour soak temperature, and then the like 6 hour cooldown phase to 600 C.
My carbon was moooostly gone, hard to tell since it was reused and it doesn’t go completely white when it’s used up. At first the part looked really good, in that it was solid (very light feeling) and held its shape! dropped it a couple times and I swear I could hear a bit of a clank… after wire brushing:
So held its shape completely. But when I tried to pull on it it went snap, boo!
It almost looks blue/purple inside.
magnification with both inside and outside in view:
It lost 10% of its weight and shrank much less than you would expect.
Next time I’ll try all recommended settings and heap on more carbon, too.