Question: What material is captain america's shield made out of?

context: Captain America's shield is virtually indestructible under normal conditions. While cosmic and magical or godly opponents have broken the shield, the shield has absorbed Hulk's blows, repelled Thor's mystical hammer Mjölnir, and deflected adamantium blades without visible damage. It is composed of proto-adamantium, a never-duplicated combination of vibranium, steel alloy, and an unknown catalyst. This material absorbs kinetic energy, transferring very little and thus preventing Captain America from feeling recoil or transferred impact forces when blocking attacks. The shield can bounce off of most smooth surfaces, ricocheting multiple times with minimal loss in aerodynamic stability or speed. The shield can also absorb the kinetic impact of a fall, allowing Captain America to land safely even when jumping from several stories, as demonstrated in "Captain America: The Winter Soldier".
question: What material is Captain Americas shield made out of mostly?
short_answers: Vibranium
Vibranium-steel alloy
Steel
context: No context provided
question: What are all the materials Captain America's shield  ismade out of?
short_answers: Vibranium, steel alloy, and an unknown catalyst

Answer: Captain America's shield is virtually indestructible under normal conditions. It is composed of proto-adamantium, a never-duplicated combination of vibranium, steel alloy, and an unknown catalyst. This material absorbs kinetic energy, transferring very little and thus preventing Captain America from feeling recoil or transferred impact forces when blocking attacks.