In the Inifnity Gauntlet comic series Thanos was able to smash Captain America's shield.
Admittedly at that point he had the full gauntlet.
So if the inifinity stones confer similar power levels in the MCU then Thanos could do it.
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In the "Fear Itself" story arch, #5, the shield was broken by the Serpent, who is an Asgardian god.
The story shows Capt.
America throwing his shield to the Serpent, who catches it, then shatters it like glass.
(see below)
There is another example, but I will link the article where I got the pic from, for the other one : Broken Shield
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With the release of Endgame , we now have confirmation that Thanos is capable of doing exactly this when he puts his mind to it, and he doesn't even have Infinity Stones at that point.
Just his brutal strength and double-bladed sword are enough.
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Vibranium, while very tough, isn't usually described as indestructible (that's reserved for the equally fictional metal, adamantium).
Even such ultra-strong metals can be broken by individuals or gadgets that can mess with matter at the atomic (or sub-atomic) level.
Thanos breaking Cap's shield is doing it with his glowing gauntlet, so is probably destroying it with infinity gem energy, not through brute force.
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I have found exactly what you want, caps shield in half, Another individual from Asgard, the Serpent is exactly as strong and menacing as he sounds.
He is the God of Fear and was freed during an "event" comic.
He begins to turn Marvel heroes into his mindless minions.
Naturally, it's up to the Avengers to bring down this tyrant.
During the epic battle, Captain America throws his mighty shield at the Serpent, but instead of taking a beating, Serpent just catches the shield and snaps it in half with his bare hands.
Luckily for Cap, after Serpent is defeated, some dwarves repaired the shield which left a scar on it from then on.
Cited from this website.
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In  Avengers: Age of Ultron , when Scarlet Witch tampers with Tony Stark's mind, he sees a nightmare of dead Avengers. There, you see Captain America's shield torn in half. It was like something cut it or broke it.   If vibranium is indestructible, then what could do this to the shield? Is there any weapon or person which is able to damage vibranium?  I'm not a fan of comics, so I don't know if there's been a mention of this.
Is there something in the Marvel universe that could cut vibranium in half?
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<marvel><marvel-cinematic-universe><avengers><avengers-age-of-ultron>
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It is generally agreed that Vibranium is not indestructible, although it is a very tough material. As a result, there are a number of instances of this material being broken. Captain America's Shield was torn in half by the Serpent, and also broken by Thanos, with or without Infinity Stones. As such, it could be argued that even Thanos' brute force would be enough to break the shield. Yes, vibranium can be broken but only by a god or by an individual using a gadget that disrupts it at the atomic or sub-atomic level.
Yes - Thanos smashed Captain America's shield in the Infinity Gauntlet series. Yes - the Serpent (an Asgardian god) breaks the shiled in the "Fear Itself" story. Yes - Thanos can break it using brute strength alone (with his double-bladed sword). Yes - it can be broken by individuals or gadgets that mess with matter at an atomic or subatomic level. This can be seen when Thanos breaks Cap's shield with his glowing gauntlet. Yes - the Serpent breaks the shield in half but it is repaired later by the dwarves.