In the *Iron Man* movies, Tony Stark's suits are made of a fictional advanced metal alloy called "Vibranium," a fictional metal with incredible strength and durability.
However, the specific composition of the Iron Man suits changes throughout the franchise. In earlier movies, it was mostly described as a "gold-titanium alloy," but later films introduced the use of Vibranium as a key ingredient.
It's important to remember that Vibranium is a fictional material created for the Marvel Universe. It's not based on any real-world metal.