Evidently they succeeded, as Bucky will be joining Steve, their Avengers allies and Wakanda’s warriors in battling Thanos’ monstrous forces during Avengers: Infinity War. But additionally, as Anthony Russo implied to We Got This Covered, it would seem that Wakanda’s brightest minds have put their resources to good use on Bucky’s new arm, and while it remains to be seen what exactly these enhancements are, I imagine that the main difference will be that the new arm is constructed out of vibranium.
In case you need a refresher on Captain America: Civil War’s final moments, Bucky Barnes and Steve Rogers were granted asylum within Wakanda, and fearing that the lingering HYDRA programming in his head would case him to hurt more people, Bucky decided to go back into deep freeze until the Wakandan scientists could find a cure for his brainwashing.