Heavens2kadonka

Hope this hasn't been discussed on this site before...

During a recent web-surfing, I came upon this site:

http://www.thebrassbow.com/brassbw1.htm#Cryogenic

So I must know...

Does anyone here have ANY idea of what this is all about? How can making a horn REALLY cold have anything to do with the sound?

gregc

Well, cryo cold can realign molecules in the brass and make the horn vibrate differently, I guess. Of course, they could just be blowing smoke up our a**.
Interesting science, none the less.

gregc

MUSICandCHARACTER

One of the most hotly controversial subjects in trumpetdom. The good people at the Brass Bow are well respected techs. They obviously believe greatly in it. Several studies have been attempted -- most with some positive results albeit with a very small sample.

The theory is that freezing the horn releases the joint stress that is put on when the horn is soldered together. Hence the reason why 30 years old plus horns are often coveted. The stress has been released. Freeze the horn, and supposedly the same thing happens.

I have seen metallurgists argue that freezing the horn will not do anything of the sort and that the results are due to the Hawthorne effect. I think many believe it is an expense they can do without. Some will try anything. It may work, it may be a placebo. Hard to do a hard core scientific test.

Thats it in a nutshell.

Jim

Heavens2kadonka

The Hawthorne Effect

In the training world, the Hawthorne effect is a chameleon. Ask several trainers and you would probably get several definitions, most of them legitimate and all of them true to some aspect of the original experiments by Elton Mayo, in Chicago that produced the term.

It has been described as the rewards you reap when you pay attention to people. The mere act of showing people that you're concerned about them usually spurs them to better job performance.

Thats the Hawthorne Effect.

Source: http://www.accel-team.com/motivation/hawthorne_01.html

(Jim,
Just had to do that, since I'm guessing I'm not the only one that read your post and said: "What the hell is the Hawthorne Effect!?!" )

Heavens2kadonka

Cryogenic tempering of metals is not a new technology, however in the last 10 years, cryogenic tempering has been acknowledged and included in the training of metallugy. It is a simple process and there are many advantages and benefits to cryogenically treating metals. One of the most important benefits is decreasing down time or set up time replacing worn out parts on equipment thus increasing the profit line. Cryogenically treating parts not only improves performance but it also increases the life of metals and parts. Another important benefit to cryogenically treat parts is to relieve the residual stress in metals during forming/forging of the part.
We have listed the most frequently asked questions to help understand what cryogenic tempering means. In every industry there are tooling, pieces, and parts than can be cryogenically treated to increase the life of those parts.

What does this do to the metal?
The metal structure changes to increase the durability or wear-life making it significantly stronger. As the temperature is lowered and raised, the molecules move in a more uniform structure to make the metals stronger which closes and refines grain structures.

What is Residual Stress?
Residual stress develops in steel during the forming/ forging and from machining required in finishing a part/piece. If the piece is not able to expand during the forming/forging then stress builds up and the life span on the part is shortened.

What kind of increase in life of a part can be expected? The increased life of a part cryogenically treated will depend on what the material is made of, but in most cases the increase can range from 200% to 500%. As an example, tools made out of M42, S7, A2 has documented increased life of 300%. Metals made from D2 such as stamping dies have been known to increase the life by 500% or more.

One of the areas we have extensive research has been treatment of aluminum. We have been working closely with government agencies along with private industries to relieve the stress to prevent cracking and breaking of this material.

How much does this cost?
We typically charge by the pound with a minimum charge of $49.50 for five (5) pounds or less.

Source: http://www.all-amer.com/ctqa.htm

Heavens2kadonka

The cryogenic process is computer profile controlled to within 1/10th of 1° Fahrenheit throughout the entire processing cycle. Items being treated are slowly taken down to -300°F., held at that temperature for a predetermined length of time, then depending on the item, slowly brought up through the processing cycle to approximately +300°F. This painstaking method eliminates the chance of thermal shock and micro cracking.

This treatment, at -300ºF for an extended period of time in a dry atmosphere changes the material's microstructure. Retained austenite (a soft form of iron) is transformed into hard martensite. A second result of the deep cryogenic "soak" is the formation of fine carbide particles, called binders, which are released and distributed evenly through the mass of material to compliment the larger carbide particles present before the cryogenic process. These smaller carbide particles help to support the martensite matrix. In addition, the deep cryogenic tempering process creates a denser molecular structure. The result is larger contact surface area that reduces friction, heat and wear.

The Results:

Increases abrasive wear resistance.
Requires only one permanent treatment.
Change the items entire structure, not just the surface. Subsequent refinishing operations or re-grinds do no affect permanent improvements.
Eliminates thermal shock through a dry, computer controlled process.
Increases durability and wear life.
Decreases residual stresses in tool steels.
Decreases brittleness.
Increases tensile strength, toughness, and stability coupled with the release of internal stresses.

Source: http://www.cryoeng.com/images/WhatIs.HTM

Heavens2kadonka

So, what I get from reading all these different sites is THIS:

They all know pretty much what it does (some go into more detail), and they all know what is the result, but the only metal they have hard evidence of improvement is aluminum (others can check to prove me wrong).

Of course, this means that the next time I have money to blow (I have been meaning to sell my Magic: The Gathering collection...), this will be my next wild experiment!!!! :P

ChasStarr

I have actually used the cryogenic process....but not on my trumpet....on my softball bats. The thin walls of the newer softball bats will dent and crack very easily (if the entire team is using them) and after having to buy new bats every year, we got together and cryogenically treated them...the result...instead of one year, the bats lasted us two and sometimes three years before replacement.

Now...the most expensive bat we had cost $249, if it sucked after we had it done, not too big a deal. I'm not sure if I want to take the chance with my new $2,000 trumpet.

PS. My softball career ended 4 years ago due to injury. Budweiser elbow. :mrgreen:

ScreaminRaider

I have the same condition

MUSICandCHARACTER

Sorry, that was a pretty grand oversight on my part. The Hawthorne Effect (if someone knows or thinks they are part of an experiment, they results will be more likely positive -- hence the need for a control group) and the Pygmalion Effect (self-fulfilling prophecies) are pretty common terms in controlled research.

My bad.