I recently saw Avengers: Infinity War and it left me pondering over:
how Iron Man was mortally wounded using a shard like object that Thanos broke off from former's arm?
As far as I could observe wide Marvel Cinematic Universe featuring him, his suit is mostly impervious to a direct but first attack, no matter if it is a close combat and no matter if literally a moon is thrown over him, as meteors of course.
In the Civil War he got bombarded by a bunch of cars from above (by Scarlet Witch and Hawkeye) yet he came out with his suit almost unscathed. Even it took lots of efforts for Captain America to destroy his (seemingly less protected) arc reactor of his suit during the climax.
Furthermore, in the Age of Ultron, I observed that that even high speed bullets didn't have any effect on his suit.
What made me wonder is that the shard was of same material as the suit was, some nanoparticle and whatnot, so it shouldn't have been able to pierce his suit. Even if it could, provided I misunderstood Mohrs scale of Hardness (or the Director(s) did), the tip of that shard would had to be so sharp and pointy as to easily pass between the nanoparticles or whatever the suit was made of. Otherwise it would have required considerable force which probably cannot be available through a close combat. As far as I could recall the shard and the type of attack didn't meet such requirements, though I might have missed them in the fast paced scenes.
So, was that successful attack technically feasible or was perhaps made to look successful because it looks badass, since Iron Man was never wounded to such scale in any movie while wearing his suit, barring some bruises and little visible injuries over his face?