We are talking about copper and silver metal alloys, not materials from a volcano!!!

The two are as different as chalk and cheese.

Mmmmm.. cheese. I could go for a pizza with a lot of cheese. You are making me hungry.

I am trying to practice, but having trouble cuz I am so dang hungry! I need to go grocery shopping.

Sorry guys, that was a bit off subject. This subject is way over my head anyway.

Kara. I understand. There are other threads which are way outside my zone of understanding too. I just keep clear of them.

Perhaps the paper clip example described in the first paragraph of this link will provide an appropriate illusration, along with the statement at the end, saying "Work hardening is removed by the application of heat."

http://www.everything2.com/index.pl?node_id=1670743

Work hardening is deliberately done in the manufacture of good quality flutes, to make the metal a lot stronger. If I heated a part of your flute up red hot, and cookled it again, it would be very. very weak, as you have no doubt experienced in Larks, and other Chinese instruments.

The volcano stuff Pico is writing about.... I don`t understand that either. It is not relevant.

"Kara. I understand. There are other threads which are way outside my zone of understanding too. I just keep clear of them."

Was that your way of politely telling me to go away? Lol!

The image is to be taken out of context of the site it came from. It however illustrates what I was trying to explain... even if deals with an entirely different subject. Google image search is resourceful.

In other words... look at the image read what I wrote. I didn`t change subjects to Volcanos.

"Was that your way of politely telling me to go away? "

No, not at all. I was making a statement about myself.. nothing more; nothing less. My thought towards you was one of understanding, which is why I offered a lay-persons explanation of the issues.

However there was another participant in this thread who should not have participated. Thankfully his/her rude, insulting post has now been deleted.

No matter how hard I try, I still have no idea where you are coming from, Piko.

Fact 1: Heating copper and silver (and quite a few other) alloys makes them soft and ductile.

Fact 2: Cold working these same alloys makes them harder and more brittle.

Fact 3: This is nothing to do with compression of the metal. It is to do with the crystalline structure in the metal.

" The heating of metal in an of itself does not change hardness..."

It DOES! Heating around red hot DOES change the hardness; it softens the metal. Every mechanical engineer knows this, both from academic study and from practical experience. So does every tool maker, every silversmith, .....

"...but the compression of the metal."

What do you mean?
a). The heating changes the compression of the metal? Not true.
b). The compression of the metal changes the hardness? Well not really. It could be compression OR stretching that does it... It is changing the crystal structure by such forces that makes the metal harder.

"The thin and thick of it all."
What do you mean? Are you talking literally, i.e. "metal thickness", or figuratively, meaning "the definitive statement on the issue"?

"The metal itself is not softer or harder."
Quite simply, it IS! If you try to dent it after annealing, then it dents easily. If you try to dent it after it is cold worked, then it is a lot more difficult to dent. Ease of denting of a metal is the formal test of softness or hardness.

"As I said before the hardness of the metal does not change only the compression...."
You would have to clarify that statement. Hardness is not an active property that goes around changing anything, so I don`t know what you mean.

"If you provide more metal content in a denser form, yes you would have a harder material or vice versa....."

Unlike gasses (and composites involving gasses), metals are essentially non-compressible, so any given alloy has a given density which is not alterable, so what exactly are you saying?

"The metal itself itself is not harder. Just the thin and thick of it all."

This does not make grammatical sense. The best I can manage is that you are saying that "Just the thin and thick of it all is harder", which is still nonsense. Perhaps you could explain in a different way.

"And we are talking, in general, of a .16" thickness of metal."

When we are talking about the effects of cold working and annealing, the thickness has zero relevance, so why bring this up?

"Annealing does increase density of metals"

First I heard of it. That is not in the engineering texts I have read. I`d appreciate a link that backs that up... not some picture of what comes from a volcano (involving gasses)

"... and as such causes a decrease in volume which by definition is compression."

Well, no! We don`t compress metals. The "compress" work, with respect to metals, is used in the sense of "this metal is under compression", meaning that a force is acting towards its surface, the opposite of a metal under "tension" .


"You`re arguing that the over heating of a metal to improve structure and remove impurities does not effect density?"

I never mentioned "over" heating, just heating, typically around red hot.
I never mentioned "improving" structure.
I never mentioned "removing impurities".
So how could any of this be part of may argument?

I never mentioned density. As I keep saying, the topic has nothing to do with density.

So please understand that I can make no sense at all about what you are saying. You APPEAR to be just putting buzz words together in a totally incoherent manner.

May I suggest you learn a bit about annealing and cold working before any further attempt to contribute to this topic. Otherwise what you are writing looks like nothing less than elaborate troll behaviour. It really is.... utter nonsense.

Oh, okay, Arak, just checking. You never can know on this forum.

Don`t know what I said to get that kind of response. The illustration was just to explain and provide visualization at what I was trying to say.

I still stick to what I said that heating in and of itself is not cause alone to change the hardness or softness of metal.

The notion that the density of metals is absolute is simply false.

Below is an excerpt from an Encyclopedia. You can also search annealing along with the words compression or density. This isn`t Witchcraft, things don`t magically become hard or soft. The phenomenon in glass is the same as in metal. I think you`re mixing the process of Forging with that of Annealing.

Encarta Encyclopedia:
Annealing -

After being formed, glass objects are annealed to relieve stresses built up within the glass as it cools. In an oven called a lehr, the glass is reheated to a temperature high enough to relieve internal stresses and then slowly cooled to avoid introducing new stresses. Stresses can be added intentionally to impart strength to a glass article. Because glass breaks as a result of tensile stresses that originate across an infinitesimal surface scratch, compressing the surface increases the amount of tensile stress that can be endured before breakage occurs.

A method called thermal tempering introduces surface compression by heating the glass almost to the softening point and then cooling it rapidly with an air blast or by plunging it into a liquid bath. The surface hardens quickly; the subsequent contraction of the slower-cooling interior portions of the glass pulls the surface into compression. Surface compressions approaching 2,460 kg per sq cm (35,000 lb per sq in) can be obtained in thick pieces by this method. Chemical strengthening methods also have been developed in which, through an ion-exchange process, the composition or structure of the glass surface is altered and surface compression introduced. Strengths exceeding 7,000 kg per sq cm (100,000 lb per sq in) can be attained by chemical strengthening

Hey Piko, don`t stress over it. We all know that Arak loves to debate anything. He is really good at it too.

I enjoyed reading your posts. You both had some really interesting things to say.

I like you Piko. I saw on another chat forum how another poster was down right rude to you, but you were very nice about it. You set a great example for everyone. I hope someday I have the pleasure of meeting you.

Piko, the metals of a flute are not glass, and contrary to what you claim, they do not behave the same as glass. Glass is an amorphous material, whereas these metals are crystalline. It is their crystalline quality that means that their hardness can be changed by heating.

"Don`t know what I said to get that kind of response."

I quoted what you said, bit by bit. And thought I had made a reasonable job of establishing it was nonsense.

"The illustration was just to explain and provide visualisation at what I was trying to say."

Either what you were trying to say was totally irrelevant (nothing to do with the metal of a flute), or communication totally failed.

"I still stick to what I said that heating in and of itself is not cause alone to change the hardness or softness of metal."

For a little education, start with
http://www.its.caltech.edu/~jsnyder/MS90/BrassHardening.html

Then how do you explain the material in that link, which is repeated at every engineering training institute.

Are you actually trying to say that the engineering institutions are all wrong, and that you are correct, your proof being some information about volcanic clouds and glass?

"The notion that the density of metals is absolute is simply false."

I did not claim that it was. However the minute compressibility of these metals is not relevant to the hardness and softness.

Below is an excerpt from an Encyclopedia. You can also search annealing along with the words compression or density.

"This isn`t Witchcraft, things don`t magically become hard or soft.`

No, they don`t do it magically. Refer again to the link I provided. They do it when we alter the crystalline structure, either by cold working (which includes cold forging) and heating, especially near red hot.

"The phenomenon in glass is the same as in metal."

Absolutely not! One is crystalline and the other is amorphous, so they behave totally differently. If you do not understand this then really you should not be posing as being knowledgeable in this topic.

"I think you`re mixing the process of Forging with that of Annealing."

That is insulting. I have made it very clear in all my other posts that annealing (for these metals) consists of heating, usually to around red hot, although there may be other much less common methods. And the opposite process, for hardening, is cold working. I deliberately did not use the term forging because that muddies the communication waters, because it includes a wide variety of processes, some of which are not relevant here.

"Encarta Encyclopedia:
Annealing - ......"

Your quote is quite irrelevant. It pertains to a brittle, amorphous, thermoplastic material. The metals of a flute are ductile, crystalline, and have a quite specific melting point. You may as well quote information on butter, or timber. These materials just are not related, so the methods of annealing and hardening have nothing in common in how they work.

A flute is NOT made of glass!!!!! Using glass as an illustration is no more relevant than using marshmallows, timber, or butter. Why do you keep bringing up totally irrelevant issues? They don`t back up your case at all!

Kara, you are too kind. I too have my bad days, thankfully not too much around here.

I`ll leave while still on the subject of Annealing...

LOVE-JOY.

AS on a window late I cast mine eye,
I saw a vine drop grapes with J and C
Anneal’d on every bunch. One standing by
Ask’d what it meant. I (who am never loth
To spend my judgement) said, It seem’d to me
To be the bodie and the letters both
Of Joy and Charitie ; Sir, you have not miss’d,
The man reply’d ; It figures JESUS CHRIST.

-George Herbert

That is beautiful, Piko! Thank you for that. Thank you for making me smile.