There's a
popular theory that the ring T'Challa inherits from T'Chaka has unspecified magical abilities with the clue being T'Challa's seemingly surprised face when his ring comes into contract with Bucky's metal arm.
Anthony Russo, one-half of the sibling director duo responsible for
The Winter Soldier,
Civil War and forthcoming
Avengers: Infinity War, recently answered a fan question on Quora on this very subject.
Said Russo,
"Black Panther’s ring is special to him because it was worn by his father, the king. When he puts it on for the first time in Civil War, it’s symbolic of him taking on his father’s role. As for it’s powers, we will all have to wait for the Black Panther movie."
Admittedly, whether the ring has any special abilities isn't truly clarified by his answer and it seems that was precisely the elder Russo's intention. It's very likely he and Joe already have the answer and have collaborated with Ryan Coogler, the solo director of the BP film.
To our knowledge, the comics have never shown T'Challa wielding a magical ring but if there are any Black Panther aficionados who know otherwise, inform us in the comment section below.