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Archive 1

Gold alloy purity

"14k gold is an alloy of gold " <- does the "k" mean carat? -- Tarquin 18:46 Dec 28, 2002 (UTC)

Yes. See also Carat (purity). -- Why Not A Duck 21:19, 17 April 2007 (UTC)
carat should be spelled out when it is used - not everyone knows this abbreviation. k also means "kilo", and K means "Kelvin", and k is also used for Boltzman's constant in physics, chemistry, and engineering.74.249.77.168 (talk) 01:00, 20 September 2008 (UTC)

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Compound?

Looks like there is an inconsistence between alloy and chemical compound: --E3c2d6ec0ca59f4588b8bb5cb621cfa6 12:42, 27 Jan 2005 (UTC)

Alloy: "An alloy is a combination, either in solution or compound, of two or more elements, [...]"

Chemical compound: "This is why materials such as brass [...] or chocolate are considered mixtures or alloys rather than compounds."

Chemical compounds have a well defined composition due to the formation of molecules. Most alloys are like mixtures and can be formed with widely varying composition even as a single phase. However there are a special cases where [Intermetallic] compound are formed. The intermetallics are usually also considered alloys, despite of there well defined composition.--Ulrich67 (talk) 13:58, 18 March 2017 (UTC)

Alloys moved to list of alloys

I removed the list of alloys and added a link to List of alloys. (That had been missing!)

I also checked whether the alloys I removed here were mentioned in List of alloys and added them there if necessary. Johan Lont 16:11, 21 December 2005 (UTC)

percentages ?

When you say "58%" do you mean "by weight"? — Preceding unsigned comment added by 198.45.18.28 (talkcontribs) 19:38, 8 May 2006

Of course. That's the way to deal with metals.74.249.77.168 (talk) 23:11, 19 September 2008 (UTC)

Is it possible to "undo" an alloy?

Here is a question that I was wondering about: if one has 12 karat 10 gram gold alloy coin, is it possible to "undo" the alloy and extract 5 grams of 99.9999% gold out of it (it does not matter what the other 5 grams are)? — Preceding unsigned comment added by 64.85.33.118 (talkcontribs) 21:51, 24 June 2006

Of coure there are methods for separating the elements out of alloys, and it is done all the time - just as metals are separated out of their ores. By melting the whole solid alloy, it is usually found that the constitutents have different densities, and they will separate out into different layers of molten metals, one floating on top of the other. Then, you just pipe off the one that you want. The metals in an alloy can also be separated by electrolysis, and in the case of elements like the rare earth elements, by using ion-exchange resins. In the iron & steel industry, there are alloys of iron and carbon that have too much carbon in them. The carbon can be removed by blowing oxygen through molten iron in what is called the basic oxygen process. The oxygen combines with the carbon, and the carbon emerges as carbon dioxide.74.249.77.168 (talk) 23:21, 19 September 2008 (UTC)

You have ten grams of high-grade gold ore. See Refining (metallurgy). —Ryan 14:20, 21 October 2007 (UTC)


can you name some please name some modern alloys and some ancient ones? lol need help for assignment, Ryan —Preceding unsigned comment added by 121.208.57.230 (talk) 04:57, 25 September 2008 (UTC)

No offense, but this is the wrong place to be asking these questions. Wikipedia:Reference desk will help you with questions like this. --Wizard191 (talk) 12:10, 25 September 2008 (UTC)

Proposed project

There is evidently no extant WikiProject which deals with articles concerning alloys and other chemical compounds. This could be a problem, as many of these articles deal with what are considered to be generally important topics. To correct this situation, I have proposed a project to deal with these articles at Wikipedia:WikiProject Council/Proposals#Chemical compounds and mixtures. Anyone interested in contributing to such a project should indicate as much there. Thank you for your attention. John Carter 20:33, 28 April 2007 (UTC)

Alloy numbering systems

How do you look up the properties of specific alloys? I was trying to find information about the beryllium bronze Glucydur, and couldn't find much. I understand there is a Unified Numbering System for alloys used in North America. Are there any similar systems in use in Europe or Asia? --Chetvorno 20:55, 11 August 2007 (UTC)

Young's modulus

Young's modulus isn't sensitive to small changes in alloy composition. It's also not appreciably affected by heat treatment or other processing. Young's modulus does not vary the way tensile strength does; it behaves more like density.

Properties of various steels:


The following source was used to support grouping Young's modulus with tensile strength and yield strength:

  • [1] Karl U. Kainer, (2003) Magnesium Alloys and Technology, Wiley Publishers, 293 pages ISBN 352730570X
    (note: URL seems to be borked, just search for the title on google books)

But this book discusses Young's modulus in the context of magnesium metal matrix composites. It's not really applicable to alloys. —Ryan 14:11, 21 October 2007 (UTC)

Making of Alloys

what are the main difference between alloy and composite matriels??? — Preceding unsigned comment added by 193.63.48.50 (talkcontribs) 14:45, 14 December 2007

The difference between alloys and composites lie at the molecular level. In alloys, the atoms are re-arranged together in a crystalline structure, but none of this happens in composites, such as in the graphite-epoxy ones that are used in electronics and aerodynamics.74.249.77.168 (talk)

An alloy is a partial or complete solid solution of one or more elements in a matallic matrix. —Preceding unsigned comment added by 216.164.144.47 (talk) 22:03, 16 December 2009 (UTC)

It's a stub

I suggest that this article be labeled as a "stub" because it is so extremely incomplete. I have added something to it, but the previous article didn't even mention solder, electrum, pewter,and it didn't mention that most alloys are harder than the primary constituents that go into them. That was the whole reason for things like the Bronze Age.74.249.77.168 (talk)

This article should not be down graded to a stub. There is too much info to be classified as a stub. It is, however, classified as a C-class to reflect its major deficiencies. We welcome any additions you have. --Wizard191 (talk) 12:44, 20 September 2008 (UTC)

Redirect of 'Substitutional alloy'

'Substitutional alloy' redirects to this article. Maybe it should have its own article? WinterSpw (talk) 07:03, 3 December 2008 (UTC)

Go for it! Wizard191 (talk) 14:07, 3 December 2008 (UTC)
I agree with WinterSpw. But I don't know what a substitutional alloy is, so could someone else please write the article and/or expand the information here? Andrew Gradman talk/WP:Hornbook 22:01, 30 October 2011 (UTC)
I don't really think it belongs in a separate article, but should be expanded upon here because this is something that is intrinsic to the nature of alloys. There are basically two types of alloys: substitutional alloys and interstitial alloys. An interstitial alloy is one like steel, where the carbon atoms fit into the interstices of the crystals. A substitutional alloy is formed by the atom-exchange method, where some of the atoms in the crystals are substituted with atoms of the other constituent. Brass is an example of a substitutional alloy, because, within the crystal structure, some of the copper atoms are substituted with zinc atoms. Zaereth (talk) 23:20, 30 October 2011 (UTC)
I went ahead and added this terminology to the article, and added a few pictures to help visualize it. Zaereth (talk) 20:29, 31 October 2011 (UTC)

Technical

As a highly read humanities and social sciences scholar, I seriously cannot get past the first sentence without needing to refer to second articles, its a bad lede. And phase is completely unexplained and unlinked. Social uses and history are underrepresented. — Preceding unsigned comment added by Fifelfoo (talkcontribs) 03:27, 29 September 2009

Single-element alloys

The following sentences indicate that iron is a single-element alloy:

  • An alloy is a partial or complete solid solution of one or more elements in a metallic matrix.
  • Alloying one metal with other metal(s) or non metal(s) often enhances its properties. For example, steel is stronger than iron, its primary element.

What I don't understand is how does iron the element differ from iron the alloy? Is it just that iron the alloy is a partial or complete solid solution? Wakablogger2 (talk) 23:33, 4 November 2009 (UTC)

I'm confused as to where you think iron is an alloy. Iron is an element. Wizard191 (talk) 14:06, 5 November 2009 (UTC)
I think I see where the confusion is coming from. The opening sentence says, "An alloy is a partial or complete solid solution of one or more elements." Naturally, this may lead one to ask, how do you get a solution from just one element. I think this may just be a typo, which has gone unnoticed. Every definition I've read says two or more elements. Zaereth (talk) 21:35, 25 March 2011 (UTC)
It says one or more .. in a matrix, and thus is not incorrect per se. Materialscientist (talk) 03:36, 26 March 2011 (UTC)
Ah, I see. I like to call this a sentence that can be read two different ways. Perhaps a simple change could help to keep it clear. Maybe something like, An alloy is a metallic matrix which contains one or more other elements in either a partial or a complete solid solution." Does that seem less likely to be misinterpreted? Also, is matrix (geology) the best article to link to from here? That article doesn't seem to have much to do with the dictionary definition; "Matrix - n. The base metal of an alloy." Zaereth (talk) 10:17, 26 March 2011 (UTC)
Actually, "matrix" implies that one component is dominant, which is incorrect in general - some alloys have comparable concentrations of the components. I would change the definition to An alloy is a solid solution composed of two or more elements. Materialscientist (talk) 10:29, 26 March 2011 (UTC)
I like that for its simplicity. However, I have always been under the impression that an alloy is primarily a metallic mixture. (Or, at least, that an alloy behaves as a metal.) I may be mistaken. Are there other mixtures of elements that are not alloys? Zaereth (talk) 10:54, 26 March 2011 (UTC)
It could be non-metal (carbon) in iron, but the resulting material should be metallic (I can't recall any non-metallic solid which would be called alloy), thus maybe An alloy is a metallic solid solution composed of two or more elements. Britannica says metallic substance composed of two or more elements, as either a compound or a solution., but I might disagree with them calling compound an alloy. Materialscientist (talk) 11:03, 26 March 2011 (UTC)
I like your definition a lot. I think we should wait a little while to see if Wizard191 or anybody else has some suggestions. If none come forth by Monday, I'll go ahead and make the change. Zaereth (talk) 11:17, 26 March 2011 (UTC)
Material scientist's new definition sounds better to me. Wizard191 (talk) 19:39, 28 March 2011 (UTC)

"Materialscientist" - Are you aware that there are actually a lot more rigorous and authoritative treatments of "alloy" than what passage you might locate in the Britannica?Wikibearwithme (talk) 22:22, 29 January 2016 (UTC)

Secondly, the introduction of this article, which you fiercely protect, is not logically the same as the passages that you quote.Wikibearwithme (talk) 22:25, 29 January 2016 (UTC)

Binary alloy

Binary alloy redirects here, but it is not defined. This definitely needs to be rectified. Wizard191 (talk) 02:09, 23 December 2009 (UTC)

As I recall, all "binary" refers to is the number of constituents that make up the alloy. There are also ternary and quaternary alloys. A good book on the technical aspects of alloys is General metallurgy by Heinrich Hofman. This article could definitely use some expanding in the technical aspects of it. I was surprised to find no mention amalgams and some of the more exotic alloys. I'm not very well versed in non-steel alloys, so I'll probably just point that out and let someone who is make the technical additions. Hope that helps. Zaereth (talk) 00:48, 5 June 2010 (UTC)

i think this is true —Preceding unsigned comment added by 59.184.48.143 (talk) 05:34, 23 August 2010 (UTC)

Homogeneous mixture

I have a few concerns about the latest addition to the lede. The way it reads now, "An alloy is a homogenous mixture or metallic solid solution composed of two or more elements," it is possible to derive two different meanings from it. The sentence can indicate that an alloy is either a homogeneous mixture or a solid solution, or that "homogeneous mixture" is the definition of solid solution.

My other concern is that an alloy is not always homogeneous but, quite often, heterogeneous, although I'm not sure that the lede is the proper place to describe the differences. Zaereth (talk) 18:23, 13 July 2011 (UTC)

Diagram

The diagram on substitutional alloys is a decent 2-D representation of such an alloy, however, I think it would be better if the blue dots were slightly smaller than the red. I attempted to make this alteration, but cannot do anything with SVG files. If someone has the ability to make this change, it'd be appreciated. Zaereth (talk) 18:48, 28 March 2012 (UTC)

Too many definitions of alloy on a single page

The article starts with one definition, and in the introduction it starts again with another definition. And again in terminology section starts with another. This needs some cleaning. I certainly cannot accept if an alloy is defined as an impure metal. An alloy continutes to be a metal even if it is not a pure substance, where by pure substance we mean, a single element. --Nagarjunag (talk) 07:09, 5 March 2013 (UTC)

Defining the concept of "alloy" is difficult to do in a single sentence. As far as I can tell, all three sentences are saying the same things, using different words. Can you explain exactly what you find confusing, or what you would change to make it better?
An alloy is not simply an impure element, because 1.) The primary element (or elements) must be metallic, 2.) the solutes typically must provide some useful benefit (for instance, wrought iron contains a significant amount of impurities, but is not considered an alloy), and 3.) the final product must have the properties of a metal. I am all for trying to come up with better, more concise definitions, but may need help to see it from your point of view. Zaereth (talk) 16:55, 5 March 2013 (UTC)
Thanks. My disconfort is due to the use of the term "pure" or "impure" to describe an alloy. I consider this a less rigorous adjective to describe an alloy and is unnecessary to explicate the character of an alloy. An alloy is a solution with one base metal acting as a solvent and another one or more elements (metal or non-metal) as a solute. We can avoid purity or impurity as properties of an alloy in its definition. Purity and impurity is relative to the purpose. Pure and impure can be used e.g. if I want to buy a gold ring, but the jeweller cheats me by adding another metal, say silver, and gives me a non-pure golden ring. In science, a solution is a state, a homogeneous mixture, it cannot be considered an impure state. When would we call a sugar syrup impure? If it contains something other than water and sugar, and not because it is no longer pure water. Often alloys are produced for a purpose and a pure metal e.g. would not be fit for the purpose. E.g. if my cycle is made of pure aluminum it will be useless for the purpose. There can be impure alloys, when the intended composition is disturbed by another unintended sustance. Hope my disconfort is clearer now. --Nagarjunag (talk) 15:50, 7 March 2013 (UTC)
That does help me better see your point of view. Thanks. I'm sure I can find a better adjective than "impure," but may need to think about it for a while. In its most common definition, the term is correct, but it can also be confusing because it has other definitions which can also fit into the context, changing the meaning of the sentence depending on how one looks at it. I can definitely describe pure syrup as being an impure sugar, and that would be a correct description, whereas "impure syrup" has a completely different meaning. (I'm not puttin' that on my pancakes.) I'll have to think about it some more.
Here's the difficulty: An alloy is not easily described as a solution either. Every alloy I can think of is a solution in the liquid state, but not always in the solid state. As an example, above ~ 1500 degrees F, steel is a solution even though it is in the solid state. Below the critical temperature, the solution separates into ferrite and cementite. The carbon is driven out of solution, forming the alloy as we commonly experience it; heterogeneous, not homogenous. So simply describing it as a solution is also not completely accurate. (A non-metallic example is honey, which begins as a homogenous solution, but eventually separates into heterogeneous phases of crystallized glucose and liquid fructose.) To complicate things further, most of the unwanted impurities will also dissolve into the mixture, and behave like solutes; the only difference being that they have an undesirable effect. It is also important to distinguish alloys from other substances which are made primarily from metals but do not behave like metals, such as many gemstones. Not easy to do. I thank you for your input, and I will try to reword the sentences to have better, more concise definitions. (It may take me a few days/weeks to get back to this.) Zaereth (talk) 17:45, 7 March 2013 (UTC)
I might add that the terms "homogeneous" and "heterogenous" can have different meanings, depending on whether talking about the macroscopic scale (the mixture) or the microscopic scale (the microstructure). It's going to take a lot of care with wording to be as precise and concise as possible in the opening sentences. Zaereth (talk) 18:11, 7 March 2013 (UTC)
The notion of Alloy has the sense of adulterating a noble metal with a base metal.
In language, one meaning of alloy, is of an admixture which stains, taints, adulterates or renders impure.
when used as a noun:
  • admixture, as of good with evil.
  • to reduce in value by an admixture of a base (less costly) metal into a noble ::::(more valuable) metal.
  • to debase, impair, or reduce quality or purity by admixture; adulterate.
when used as a transitive verb:
  • to reduce in value by an admixture of a less costly metal.
  • to debase, impair, or reduce by admixture; adulterate.
examples:
(1) "Nevertheless, this public joy was mixed with some tears, and the present happiness was alloyed by the remembrances of the miseries they had endured."
from "Plutarch's Lives" by Plutarch, translated.by: John Dryden, ed.by: A.H. Clough, Random House(1864)
(2) "It was a quiet holiday with us afterwards: a brief passage of hours whose happiness was alloyed only by anxiety to get news of my mother."
from "My Danish Sweetheart" by William Clark Russell (2012)
ramrao (talk) 04:50, 8 March 2013 (UTC)
Well that has more to do with the word itself rather than the substance it describes. In an older sense "alloy" often did have a connotation of a reduction in quality (with quality being a synonym for purity). Thus, alloyed gold was of less quality than pure gold. However, from a metallurgical standpoint, an alloy often represents an increase in desirable qualities. Since the early 1900s, the term has had much less association with adultertion and more with strengthening. "In the face of overwhelming odds, the two factions alloyed their forces in a last defensive stand." The word comes from the Middle French "aloi," meaning "a mixture."
Unfortunately, as much as I love etymology, an encyclopedia is about the thing and not the word. (Dictionaries are about words.) The goal here is to define the noun, that is, the actual substance. Zaereth (talk) 05:49, 8 March 2013 (UTC)

Spelling of 'aluminium'

Aluminium or Aluminum? Isn't aluminium the standard (IUPAC) name that is preferred, so why should it not be used in the article? — Preceding unsigned comment added by 142.136.170.168 (talk) 23:54, 17 August 2013 (UTC)

 Done. Aluminium not Aluminum, per WP:ALUM. — Reatlas (talk) 06:47, 18 August 2013 (UTC)
Hmmm. Well, this is the first time I've seen the policy; let alone the term "aluminium." it's quite a tongue-twister to try and say. I'm not sure I would've ever noticed if someone hadn't pointed it out. (I guess I wasn't really thinking of this article in terms of chemistry either.) My apologies, and thanks for the correction. I'll try to remember this in the future when working on chemistry-related articles. Zaereth (talk) 00:44, 22 August 2013 (UTC)

article needs to stick to meaningful, technical definition

This article continues the relatively recent habit of those particular asian academics who have limited english training, to refer to any solid compound as an "alloy" in certain research publications having not to do with metallurgy. This casual usage effectively eliminates any usefulness for this term, and is contrary to the historical usage as a metallurgical term ( for discussion above, if you like poetic license, go to a poetry article). Sapphire, quartz, silicon carbide, etc, etc, are refractory compounds that have nothing to do with the historical use of the term "alloy" - for insight on this, one can look at the various texts that treated the physics of alloys when this science (and terminology) was being responsibly extended and rigorously defined over the last two centuries. For example, see the seminal texts of Mott, other famous physicists recognized for studies in "alloys" . Alloys are defined as intermetallics and various solid solutions thereof, NOT a some loosely defined compound (or mixture) of a metal and "some element." Wikibearwithme (talk) 22:06, 29 January 2016 (UTC)

First, this article is intended for a general audience, so technical definitions need to be simplified and spelled out clearly, especially in the beginning. The lede itself is merely a summary of the entire article, so any changes to the lede need to be properly written and sourced in the article first. Second, a solid solution or an intermetallic are only part of the definition of an alloy. Steel is an excellent example, which, just a hundred years ago wasn't even considered an alloy. Steel is not an intermetallic, and is only a solid solution when its above the upper critical temperature. Below this temperature and it becomes a heterogeneous mixture. Other solutions such as ruby and titanium sapphire are composed mostly of metals, but of course do not behave like metals, thus are not considered alloys. Until you actually try to define all of these features in a single, simplified sentence, then it really becomes unapparent just how much work must go into it. (Not to mention that an alloy may also be a liquid solution.)Zaereth (talk) 23:10, 29 January 2016 (UTC)

Simple, clear definitions are fine - incorrect definitions are another thing, however. The introduction contradicts itself. The first sentence makes the definition vague and almost meaningless. The first sentence is not properly sourced (unless you rely on the recent popular corruption of the term, in which case, you can say almost anything you like - this is precisely my issue with this). Secondly, where are you getting your terminology? Ruby, sapphire are absolutely not solutions (doped or not doped with impurities); they are compounds (Al2O3). The generic "steel" is in all cases a solid solution, regardless of whether or not it involves a two-phase field. I haven't claimed that steel is an intermetallic - though, referring to cementite as an "intermetallic" certainly has far more scientific merit than the opening sentence of this article.

The second sentence of the introduction paragraph is great; I would recommend making the first sentence consistent with it. Wikibearwithme (talk) 02:50, 30 January 2016 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Alloy/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

end of 2nd section: kim is silly? makes me doubt the validity of this entire article

Last edited at 05:58, 5 August 2007 (UTC). Substituted at 07:25, 29 April 2016 (UTC)