Difference between revisions of "Thermal stability"
(improvements) |
(added links to other stabilities intro) |
||
| (2 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
{{stub}} | {{stub}} | ||
| + | |||
| + | The strength of constraint for thermal stability is typically between <br> | ||
| + | * the stronger requirement of [[chemical stability]] and ... | ||
| + | * the weaker requirement of [[mechanical stability]]. | ||
| + | |||
| + | == Thermal stability issues are totally not a show stopper == | ||
| + | |||
| + | For temperatures at and around room temperature there are many attractive materials (and structures out of these materials) <br> | ||
| + | that [[for all practical purposes]] do not experience any undesired diffusion atom hopping events. | ||
| + | |||
| + | Even for significantly higher temperatures (like e.g. what one encounters on Venus ~500°C) <br> | ||
| + | there are plenty of materials ([[Refractory compounds]] - melting points >2500°C - including cheap [[Moissanite]]) | ||
| + | that still experience insignificant diffusion. | ||
| + | |||
| + | == What to look out for == | ||
| + | |||
| + | Most critical for thermally induced undesired diffusion hop events are: | ||
| + | * [[Surface diffusion]] (and [[Surface reconstruction]]) – especially crystal edges, steps, and "steps of steps" | ||
| + | Locatins with high local mechanical tensions like e.g. | ||
| + | * on grain boundaries from production via [[thermodynamic means]] | ||
| + | * in step or screw dislocations | ||
| + | |||
| + | [[Piezochemical mechanosynthesis]] does neither produce grain boundaries nor produce step or screw dislocations <br> | ||
| + | with high tensions inside them. Well, unless it's done with very deliberate intention. <br> | ||
| + | Edges and steps can be tailored to the thermal demands. <br> | ||
| + | |||
| + | '''Some extreme example application cases are:''' | ||
| + | * Internals of [[rocket engines]] | ||
| + | * [[nuclear fusion|Fusion]] power plants | ||
| + | * Mining robotics for [[Venus]] | ||
| + | * ... | ||
== Related == | == Related == | ||
Latest revision as of 11:41, 25 July 2021
The strength of constraint for thermal stability is typically between
- the stronger requirement of chemical stability and ...
- the weaker requirement of mechanical stability.
Thermal stability issues are totally not a show stopper
For temperatures at and around room temperature there are many attractive materials (and structures out of these materials)
that for all practical purposes do not experience any undesired diffusion atom hopping events.
Even for significantly higher temperatures (like e.g. what one encounters on Venus ~500°C)
there are plenty of materials (Refractory compounds - melting points >2500°C - including cheap Moissanite)
that still experience insignificant diffusion.
What to look out for
Most critical for thermally induced undesired diffusion hop events are:
- Surface diffusion (and Surface reconstruction) – especially crystal edges, steps, and "steps of steps"
Locatins with high local mechanical tensions like e.g.
- on grain boundaries from production via thermodynamic means
- in step or screw dislocations
Piezochemical mechanosynthesis does neither produce grain boundaries nor produce step or screw dislocations
with high tensions inside them. Well, unless it's done with very deliberate intention.
Edges and steps can be tailored to the thermal demands.
Some extreme example application cases are:
- Internals of rocket engines
- Fusion power plants
- Mining robotics for Venus
- ...
Related
- Chemical stability
- Thermal stability (this page here)
- Mechanical stability
- Refractory compounds
- Diffusion transport
- Surface reconstruction
- Thermal damage
- Thermal motion – Brownian motion
Common misconceptions about atomically precise manufacturing & Thermodynamics:
- concerns about thermal motion preventing practical piezochemical mechanosynthesis or even ...
- concerns about thermal motion preventing sufficient stability of the synthesized structures
Neither of these two concerns hold on closer inspection.
