Wear
There is no wear in diamondoid crystolecular machine elements (or more generally gemstone-like molecular elements).
See: Examples of diamondoid molecular machine elements & Atomically precise bearings.
Or rather the concept of wear is not even well applicable.
There are other damage mechanisms.
Atoms don't wear. They are FAPP are eternal.
(Ionization is reversible and transmutation is not happening from mechanical sliding).
A molecule of two atoms also doesn't wear. Though it can break.
Small nanoscale bearings like atomically precise slide bearing are
are flat with atomic precision and "infinitely clean".
That is: Not a single atom of dirt is inside.
So there cannot be failure from self-interaction. And wear is not an applicable concept.
Wear is a statistical process inherently needing a large number of parts to be an applicable concept.
Note: Wear and friction are often considered intermingledly.
For a discussion of friction in the context of gemstone metamaterial technology
see: Friction in gem-gum technology
Contents
Exceptions – Actual wear
For the sake of lowering friction there seems to be some motivation
to go for atomically precise roller gearbearings of bigger sizes.
Note that this could still be combined with a infinitesimal bearing approach.
Especially for larger superlubricating toothflank gearbearings
there are two pathways for actual wear top happen.
- Seal failure and damage from entering matter
- Subsequent further damage after damage from other damage mechanisms
Seal failure and damage from entering matter
As atomically tight seals are easy in gem-gum-tec (see PPV) so is preventing dirt from entering.
Though for the sake of minimizing friction a seal on every bearing might be ditched
in favor of a seal for a larger subsystem.
A broken seal allowing in loose matter that can get squished and break structures like e.g. gear-teeth.
It's the classical "wrench in the gears" situation.
Though the smaller the machine element the more discrete and digital the progress of failure will be.
From A-Ok straight to badly or fully broken rather than slow sneaky very gradual degradation in performance.
A decrease-in or total-absence-of performance
due to permanent clogging is another failure mode.
Though this is usually not considered to be wear.
Subsequent further damage after damage from other damage mechanisms
Subsequent further wear from initial damage incurred form other mechanisms.
E.g. Heavy ion radiation caused some serious deformations that
through movement now crash into other still intact structures damaging them too.
For this to be called "wear" the bearing needs to be large enough such
that the additional damage is progressing at least somewhat gradually.
Non-wear damage mechanisms
Dominating damage mechanisms include:
Radiation damage
See: Radiation damage
Softer UV can often be insuffizient to cause damage.
Unlike in proteins or DNA atoms are in a 3D crystal such that
broken bonds are kept in place and can reform again.
High energy particle radiation can cause heavy damage
thermalizing (more or less melting) quite some local volume.
Thermal damage
See: Thermal damage
Going near the melting point can cause serious damage.
Some spots more prone to destructuring than others.
Above melting point obviously means total annihilation.
Not that there there are some correlations between
thermal, chemical, and mechanical stability.
Like e.g. highly stained bonds will be the first
to escape metastable states to thermal equilibrium.
Simple non-strained structures like moissanite will be extremely resilient.
Most critical is perhaps fusion from depassivation.
That is: Unintentional seamless covalent welding as the
hydrogen atoms that cap the surfaces escape.
Replacing hydrogen atoms on surfaces with fluorine atoms might help.
