It doesn't become metal, although harvesting it is a challenge. The telltale signs of ironbark is a somewhat blue tinge, and the tree can only be found in the Brecilian Forest.

I believe the technique is somewhere between the two: tempering, heating, as well as carving. Otherwise, I'm not too sure about the other aspects of forging with the material.

If I can uncover more details for you, I will be happy to do so.