SandyCastings wrote:
With titanium being so reactive above 450f will it not still need to be cast free of nitrogen and oxygen and maintained in purge until it cools? Thats kind of how it work for welding otherwise you end up with brittle bubbly sugar instead of welds that look like liquid mercury.
That is a concern. With my furnace design, it gives the melt time to "off gas" before hardening. The mould will be purged with helium prior, and the charcoal fire will use most, if not all the oxy in and around the ingot mould. It works for ferrous stuff. We will se if it works for Ti alloy.
I keep seeing the thermite burns and molten metal dropping onto the groung, looks cool, but has anyone actually produced a useable part? stick a mold under it guys!!
Yes, I agree. Most, if not all those thermite runs are for show, and after several trials, I've learned that you need to pack the charge tightly, put a lid on it and have a hot ingot crucible/mould. Then you can harness the awesome power that thermite gives you. You can even make tungsten alloys.
Here is a pic of my basic furnace. I call it the star chamber. The lid and insulation, plus the extra heat source, produces a reaction flame estimated at close to 8000 F. The iron can reach boiling, and often does. 8000 degrees is close to lower fusion temps, hence the name.
