The records attached to the Voyager spacecraft are apparently just like an old-school vinyl disk, except made of gold (sort of like a metal master), in that the information is encoded in mechanically cut grooves. Based on depictions of the spacecraft, it appears that while the record is attached to the outside of the vehicle body, the playing surface is facing in (presumably for both protection and to display some engraved illustrations). In the series "Cosmos: A SpaceTime Odyssey", Neil deGrasse Tyson states rather simply that the record should still be playable in a billion years, but says nothing about the duration as either a minimum or a maximum, or how the recording may be emperiled.
Assuming the Voyager craft don't crash into anything, and encounter nothing larger or more substantial than cosmic ray particles, what would be the limit at which the record would still be in a playable condition? And by what mechanisms might it be damaged to the point its recording could no longer be played (or its content no longer recoverable by any known means)?
Would cosmic radiation eventually erode the entire spacecraft into dust? If it remained in cold insterstellar space, never to encounter anything but cosmic radiation, could it remain intact for the projected life of the universe?
The point of my question is this: Is there (or are there) any process(es) which is/are entirely unavoidable by which the recorded content is doomed to eventually become lost, perhaps even while some semblance of the original spacecraft still remains? Is the entire vehicle utimately doomed to certain destruction within the projected life of the universe? Conversely, if not vaporized, smashed, or otherwise damaged in some sort of encounter(s), would the recordings be more or less guaranteed to remain intact and playable if the craft is found by some intelligence, no matter how far into the future that might be?