Board Thread:General Discussion/@comment-17727336-20150308040727/@comment-746824-20150420033716

Tony Stark's New Element is based of off the Tesseract. The rights to Adamantium are tied with the X-Men rights, meaning that so far, adamantium does not exist in the MCU.

Additionally, adamantium is not a vibranium alloy at all. In fact in the comics, Captain America's Shield is actually made from a Vibranium/proto-Adamantium mix.