They continued: “Maybe that’s how he was able to make the nanotech suit we see in Infinity War and Endgame?
“The properties of Vibranium enabled him to make new technology like nanotech in [much] less time.
“Tony Stark and T’Challa never interacted on-screen but they might have interacted after Civil War when Cap left him on Siberia and possibly became friends.
“Even in Spider-Man: Homecoming, Happy references of a new shield for Captain America and Tony wouldn’t have made it with any other metal because that would be useless for Cap’s fighting style and the villains he fights. So it is more likely that Tony used vibranium to make that shield.”
source: express.co.uk