interesting quote regarding cryo treatment

[Doc B.]

Tests done by Boeing/Sunstrand demonstrated cryogenic processing extended the life of circuit boards in military applications, specifically boards used in cruise missiles. Tests done by Honeywell on experimental thin film magnetic memory wafers showed increased conductivity of metallic layers, reduced residual stress between layers, and possible (but not fully confirmed) "healing" of vacancies in the layers. Tests on transformers showed treated transformers had significantly less hysterisis. The magnetic core saturated less. Tests on transistors showed a decrease in rise time. Other tests indicate greatly increased contact life on relays, switches, and circuit breakers.

I found this quote on a thread on the gearpage having to do with cryo treated guitar pickups. Don't know the original source

[johnsonad]

It might be cool to dip a pair of OPT and A/B the sonic results.  Thanks for posting this Dan

[Doc B.]

We have compared, many years ago. What I recall was that the cryo'd trans sounded a little more smooth and "broken in".

[Paul Joppa]

My recollection is that the difference was incredibly tiny. These were Magnequest B7-5K preamp output transformers, with low-nickel cores. I still have the test box, it was a parafeed amp with switchable amounts of plate choke inductance. A 10% increase in inductance was much more clearly audible than the difference between the OPTs. Thing had Infinicaps at the output - those were hot stuff back then. (I just pulled it out to check.)

At around that time, everyone who tried agreed that de-magnetizing your tubes was seriously worthwhile. Haven't heard much about that recently. Of course, we were also de-gaussing our CDs and painting the edges green back then.

[earwaxxer]

I am still very resistant to such 'tweaks'. Mind you, I come from the camp of 'wire is wire'. I have learned more since, but the 'quantum' stuff etc. is still snake oil to me.

[2wo]

Hmm,  All this time I've been painting the whole CD green...John

[earwaxxer]

I havent done that, but I do have MANY boutique fuses. So there.

[saildoctor]

Huh - I wonder if the extended circuit board life could be attributed to reducing tin whiskers?

http://nepp.nasa.gov/whisker/background/index.htm

[Grainger49]

   .  .  .   At around that time, everyone who tried agreed that de-magnetizing your tubes was seriously worthwhile.   .  .  .   Of course, we were also de-gaussing our CDs and painting the edges green back then.

Now I have a use for that old bulk tape demagnetizer I have.

[corndog71]

Now I have a use for that old bulk tape demagnetizer I have.

Hah! I still have one of those!

[Armaegis]

How exactly does one increase the life of a cruise missile? I mean... it goes boom. Not much life beyond that. 

Cryo treatments have the potential to induce phase changes/precipitation or recrystallization in materials, particularly if they are under a lot of stress (as thin films tend to be, depending on the method of manufacture).  Such changes then will typically result in a reduction of said residual stress. Larger bulk materials would likely benefit more from a heat treatment and more careful manufacturing methods than a cryo "fix".

[4krow]

What hasn't been cryoed? I saw an experiment with expensive blades for hand planes that had undergone this treatment. Much to the praise of the hand plane company that did the experiments, they said that there was no significant advantage for this treatment. Yah blades and tubes and wire are all different, so I am open to anything that might improve performance for a particular part. It's just that so often, in such discoveries, it is sold as the 'answer'. They call it marketing. On the other hand, there quite a few things that are worthwhile to try. Maybe that is our job.

[STURMJ]

You can order your favorite razor cartridges cryo'ed. They are expensive (more than usual ) , but I have heard good reviews.

[docbob52]

Very interesting post.

As a dentist, I daily employ various heat and cold treatments in the lab to change the grain structure of various metals (usually gold, copper platinum and palladium) in order to alter their physical and working properties.  The changes in the microscopic grain structure after cryogenic or heat treatment is clearly evident under a scanning electron microscope and is taught in all metallurgical engineering curriculums. It has in fact been used for thousands of years dating back to the metal artisans in ancient china. 

Denis Boyle the electrical engineer who owns Chimera Labs,  advocates and sells cryogenically treated OCCC wire in all his litz braided wire and cables.  http://www.chimeralabs.com  I have a bunch of his raw wire here and have used it for numerous DIY cables and internal wiring.  Dennis is one of the most knowledgeable Valve SET guys I have had contact so I am confidant that there is really something to it.  Unfortunately, for me Litz braiding over 3 strands as a bitch for me!

http://www.chimeralabs.com/faq.html

[4krow]

cryo treatment does tug on me now and then. I want to ask what happens to a tube that was first cryoed, changing the grain structure of it's metal parts. Then when heated to operating temps, does that undo the 'goodness' of cryo treatment in the first place? Kind of like taking the temper out of a blade. All in all, I think that there is much that we don't know, but that doesn't mean it is suspect.