Talk:Vibranium/@comment-32165814-20180419155739

It is later revealed that the Winter Soldier's first prosthetic arm was comprised of titanium; by vibranium, as that is the reason why it was easily destroyed by Iron Man's repulsor.

But this time, Bucky Barnes is given a new prosthetic arm that is comprised of pure vibranium by Shuri, so the next time he and Tony Stark encounter each other again, it will not be destroyed so easily by the latter's repulsor.