Vibranium

Vibranium is a rare element from Marvel Comics. The Vibranium comes from Wakanda, a small conutry in Africa and is the rarest metal of Earth.

Iron Man 2
After watching a video of his father, Tony creates a new element to replace the Palladium, which has poisoning his blood. Altough unnmaed in the movie, the novelizations recognizes it a Vibranium.

Captain America: The First Avenger
While the Captain America and Howard Stark talked about women, Rogers became interested in a circular shield, Stark says it's only a prototype. Rogers intrigued asked that was made, Howard replied that's Vibranium, the rarest metal on the planet, as strong as steel and third of the weight and also absorbs the vibrations.

The Avengers: Earth's Mightiest Heroes
The Vibranium from which the shield was made was sent as a gift to President Roosevelt from T'Chaka. Howard Stark used the vibranium to create a unique battle shield for Captain America to use it as his main battle weapon to fight against HYDRA during World War II. Before this he used a different shield based on the same design but this shield was different from the next version. The vibranium was obtained when Panther's father gave it to Howard as a gift.

Klaw with a group of mercenaries going to Wakanda to steal the Vibranium, after killing the S.H.I.E.L.D. agents, Klaw and his men take the Vibranium but Hank using his powers manages to defeat the mercenaries and Klaw, Klaw runs away scared when is defeated by Ant-Man.

Later, Hank continues studying the Vibranium after the problem.