It is well known that zinc, like all metals with low melting temperature, flows slowly under high stress.
So this failure was easily predictable. I assume that the cables have been designed for a much shorter lifetime, so it was expected that either the cables would be replaced or the radiotelescope would be decommissioned many years ago.
Nevertheless, the choice of pure zinc for the cable sockets is somewhat weird, because it guarantees a short lifetime. Had a zinc alloy been used, like ZAMAK (Zn-Al alloy), the flowing speed would have been much less and the lifetime of the cables would have been greater.
Alloys are much more resistant to plastic deformation and flowing than pure metals, because the atoms with different sizes cause defects in the crystal structure that prevent the easy slipping of the atom planes over each other.
So this failure was easily predictable. I assume that the cables have been designed for a much shorter lifetime, so it was expected that either the cables would be replaced or the radiotelescope would be decommissioned many years ago.
Nevertheless, the choice of pure zinc for the cable sockets is somewhat weird, because it guarantees a short lifetime. Had a zinc alloy been used, like ZAMAK (Zn-Al alloy), the flowing speed would have been much less and the lifetime of the cables would have been greater.
Alloys are much more resistant to plastic deformation and flowing than pure metals, because the atoms with different sizes cause defects in the crystal structure that prevent the easy slipping of the atom planes over each other.