1. While there is a lot of information on cryogenics out there, a lot of it is simply incorrect. This thread is no exception, unfortunately...caveat emptor.
2. The specific transformation I mentioned is a
Diffusionless transformation. In other words, nothing within the material has to move through the lattice to effect the transformation. I provided a reference which discusses the change from a Face Centered cubic crystal structure, to a Body Centered Crystal. It requires NO diffusion, or transport, of atoms through the material to affect the change. This is unlike a silver or gold plate over copper, where the metal will indeed diffuse into the copper.
3. The alloy I speak of freezes in a specific lattice pattern, FCC, and leaves within the lattice, Potential energy..not excess kinetic energy, that is a silly description....POTENTIAL energy. The verbage "excess kinetic in the material" comes from one who does not understand physics very well. Either the source is uninformed, there was a translation error, or a marketing person massaged correct information into what is written. Proofreading would have helped here.
4. Glue is NOT used as a hermetic seal for vacuum tubes. They are not capable of preventing molecular diffusion of gases. The seals are actual atomic bonding of the glass of the envelope to the metal of the leads. Note: Sometimes, it is not an atomic bonding process at all, but just very very intimate contact like a compression seal.
5. While the FCC to BCC transformation does indeed alter the density, that change will not be measureable outside of the NBS lab. Nor, will the conductivity change be measureable, as current technology meters that can be purchased are only capable of 1 part in 10 to the 10th resolution.Note: this also requires the material being measured be temperature stable and measured to accuracies in the millikelvin range. Trust me, that is not very easy.
6. Grain boundary interactions (and cryo annealing to alter such) with electrons remain UNMEASURABLE using current technology at room temperature...it's in the numbers also. The difference can indeed be measured at liquid helium temperatures, as the dislocations will affect the mean free path of collisions between the electrons and the lattice structure. At 4.5 Kelvin, a very good copper will exhibit
three orders of magnitude BETTER conduction than it does at room temperature, mean free path being 4 to 10 cm, as opposed to hundreds of nanometers.
Alan: While I do not concur with the audio benefits of cry treatment, I also cannot discount it. I have not used cryo on audio components, "just other stuff". Other than that earlier sentence I had ta tweak ya with
, everything you are saying w/r to cryo processing I find refreshingly accurate.
I would mention one finer point: Many insulators are capable of surviving a well controlled cryo treatment, but be careful that the wire is not bent too tightly. If a wire is too tightly bent, the insulation may crack at the bend. This is VERY important for hv and AC lines, as they can hit chassis.
Cheers, John
