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asaa...@gmail.com

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Apr 20, 2017, 1:29:11 AM4/20/17
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I am research student I need any one interest in casting of copper base alloy or high copper alloy with chrome in different ratios (0.46 - 5)% chrome and copper base alloy with aluminum in different ratios (3 -9)% Al ,I need know how can cast of chrome in molten copper that has 1907 C temp whereas the copper 1085 C, can I add chrome to molten copper as powder? Did the chrome dissolved in molten copper.
then I will try to make solution treatment to these alloy for strengthening (quenching and aging) to ...then I will to compare between these alloy with mechanical properties, corrosion and wear resistance. Please if you any one can help me to achieved these requirements. Did the copper chrome alloy has more than properties from copper aluminum alloy with the ratios above
Thank with my regards

David Billington

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Apr 20, 2017, 12:33:37 PM4/20/17
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You would need to know the solubility of chrome in copper to know how
much you can add but modern pewter (Britannia metal) is made by melting
tin and then adding the copper and stirring to dissolve the copper.
Copper has a much higher melting temperature than tin but will readily
dissolve up to a point.

Tim Wescott

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Apr 20, 2017, 1:06:06 PM4/20/17
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Most of your questions I can't help you with, but the fact that you don't
know if chromium is soluble in copper tells me that you haven't done your
homework.

A Really Short Web Search tells me that chromium-copper systems are
pretty complex: apparently chromium isn't miscible in copper, so you have
to work hard to get a nicely distributed suspension. This is NOT a
question that you're likely to get answered on an amateur metalworking
group (although there may be some enthusiast or retired metallurgist who
knows, in which case I'll be interested in seeing the answer myself).

I think you have some research papers to seek out and read.

--
Tim Wescott
Control systems, embedded software and circuit design
I'm looking for work! See my website if you're interested
http://www.wescottdesign.com

Tim Wescott

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Apr 20, 2017, 4:01:48 PM4/20/17
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I did a bit of searching and based on the little bits I found it seems
they're imiscible.

I was hoping to find a master chart of the solubilities of all metals in
all metals -- I was disappointed.

David Billington

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Apr 20, 2017, 4:16:07 PM4/20/17
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I was reading recently about modern pewter (Britannia metal) and it's
typically 92-6-2 for rolled sheet with slight variations depending on
application. That's 92% tin, 6% antimony, and 2% copper. Apparently the
antimony also helps keep the copper in suspension and evenly distributed
as IIRC the copper would separate out and IIRC not much more copper will
dissolve in tin anyway. I've not looked for information as you have
about the copper chrome combination but maybe in a similar way another
element addition might boost take-up, I think I'll leave that to the OP
as I can't see I have any need for playing with a copper chrome alloy.

Jim Wilkins

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Apr 20, 2017, 4:21:25 PM4/20/17
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"Tim Wescott" <t...@seemywebsite.com> wrote in message
news:QOKdnWWFHN3ld2XF...@giganews.com...
Phase Diagram:
https://www.andrew.cmu.edu/user/dl0p/laughlin/pdf/039.pdf
It shows how the solubility of chromium in molten copper increases
with temperature.

Eutectic:
http://csmres.jmu.edu/geollab/Fichter/IgnRx/BinryEu.html

-jsw


edhun...@gmail.com

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Apr 20, 2017, 4:23:51 PM4/20/17
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Copper and chromium are not miscable, but they are somewhat soluble, and there is a whole class of copper/chromium alloys:

https://www.copper.org/resources/properties/microstructure/chrom_cu.html

When the alloy is cooled, the chromium either goes into solid solution (fast quench) or it precipitates out (slow quench). The usefulness of the alloy depends upon further heat treatment, which allows a fine matrix of chromium to precipitate out of the alpha copper, resulting in a very strong, precipitation-hardened alloy.

You probably can find more by looking up the individual Copper Assn. alloy numbers, which are listed in the article linked to above.

Corrosion resistance of precipitation-hardened alloys typically is not very good, but I have no idea about this pair.

As for the aluminum, I'd start with the big handbooks from the American Society for Metals. I can look it up but it's worthwhile for the OP to make himself familiar with the resources. This is pretty obscure stuff and you have to find your way around the basic references if you're going to get anywhere with complex and obscure questions such as these.

--
Ed Huntress

Jim Wilkins

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Apr 20, 2017, 4:35:22 PM4/20/17
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<edhun...@gmail.com> wrote in message
news:c3ed5331-7818-4453...@googlegroups.com...
================

The copper-aluminum alloy is called a Bronze:
https://en.wikipedia.org/wiki/Aluminium_bronze
-jsw


edhun...@gmail.com

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Apr 20, 2017, 5:12:19 PM4/20/17
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I think he said chromium/copper/aluminum, but yeah, plain aluminum bronze is quite common -- and very strong.

With the chromiun/copper, the question is whether he wants a solid solution or the precipitation-hardened version. The precipitation process is commonly called "aging," but I don't know if this alloy will age naturally, like 6061 aluminum.

--
Ed Huntress

Asaad Kadhem

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Apr 20, 2017, 5:33:22 PM4/20/17
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Thank Mr. David ...the solubility of chrome in copper about 1.5 %...I understand from your massage can I add chrome powder to copper....thank

Asaad Kadhem

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Apr 20, 2017, 5:41:22 PM4/20/17
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Thank Mr. Tim Wescotti ....research and read more papers ...but some of problem in practice or some things can not be includedcan in papers

Asaad Kadhem

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Apr 20, 2017, 5:50:33 PM4/20/17
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Thank Mr.Ed Huntress ...I read that and your words very true but I need some one who is expert in casting in the workshops because in practice the melt and cast very difficult

edhun...@gmail.com

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Apr 20, 2017, 6:47:00 PM4/20/17
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On Thursday, April 20, 2017 at 5:50:33 PM UTC-4, Asaad Kadhem wrote:
> Thank Mr.Ed Huntress ...I read that and your words very true but I need some one who is expert in casting in the workshops because in practice the melt and cast very difficult

This is more complicated than you're reading here. For over 100 years, they've made copper/chromium alloys by melting, but they achieved only about 0.5% chrome that way. Higher alloys, up to 10%, have been achieved by aluminothermic reaction (like thermite).

You need the papers. Don't assume you can just dissolve chromium into molten copper and come up with a 1.5% alloy.

--
Ed Huntress

et...@whidbey.com

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Apr 20, 2017, 8:07:31 PM4/20/17
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On Thu, 20 Apr 2017 14:50:28 -0700 (PDT), Asaad Kadhem
<asaa...@gmail.com> wrote:

>Thank Mr.Ed Huntress ...I read that and your words very true but I need some one who is expert in casting in the workshops because in practice the melt and cast very difficult
Greetings Asaad,
An expert in casting will not be able to give you the advice you need
on this newsgroup because there is too much information to type. So
you really need to get a book aboput casting. Since you are totally
new to this I think a book written so for folks like you would be
best. One that has the casting basics but also enough information so
that as you get more experience there will also be information you can
use. So try this book. "The Complete Metalsmith" by Tim McCreight. The
book covers many aspects of metalsmithing which you may find
interesting but the section on casting is really good for beginners.
It tells you about various fluxes, why they are needed, how they work,
and how to use them. You will need to know this to do the casting you
want to do. The book also covers heat sources and crucibles. I hope
you learn something that you can tell us all about.
Cheers,
Eric

edhun...@gmail.com

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Apr 20, 2017, 8:45:15 PM4/20/17
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That's good advice -- he really needs to know which questions to ask -- but, as one who covered materials, including casting, in the metalworking press for 40 years, I would be very surprised if he finds answers to his specific questions in any ordinary casting book.

I doubt if chromium/copper alloys are cooked up in any ordinary casting operation. It's a specialty and the only people who are likely to know about it are well-educated casting engineers. Finding one working in a foundry who can talk authoritatively about site-mixed chrome/copper (plus aluminum) is something I wouldn't even try.

When I had to answer arcane questions like that, I'd go straight to the associations who know the highest-level engineers in the field I'm inquiring about. They're geared toward educating people about their industry; they're usually very helpful at connecting you with the people who are most likely to know.

In this case, the two organizations I'd try would be ASM International (formerly the American Society for Metals), and the ICA (the International Copper Association). Here are their websites:

http://copperalliance.org/

http://www.asminternational.org/web/guest/home

Like most industry associations, they have staff that deals with the press, so I always had an easy way in. But they're also geared toward helping students and educational institutions. They're the most likely places to reach someone who really knows the answers.

--
Ed Huntress

et...@whidbey.com

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Apr 20, 2017, 9:37:56 PM4/20/17
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I figger before he can start experimenting with new alloys he needs to
understand the fundamentals of melting and casting small ingots. Once
he has that down pat he can start to experiment. Of prime importance
is the heat source, type of crucible material, and how to avoid
oxidation of the melt. No matter which course he decides to take he is
gonna need to do lots of reading. The links you posted will be a good
start in the reading dept.
Eric

rangerssuck

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Apr 21, 2017, 10:30:41 AM4/21/17
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On Thursday, April 20, 2017 at 9:37:56 PM UTC-4, et...@whidbey.com wrote:

> I figger before he can start experimenting with new alloys he needs to
> understand the fundamentals of melting and casting small ingots. Once
> he has that down pat he can start to experiment. Of prime importance
> is the heat source, type of crucible material, and how to avoid
> oxidation of the melt. No matter which course he decides to take he is
> gonna need to do lots of reading. The links you posted will be a good
> start in the reading dept.
> Eric

That would depend very much on whether his research is theoretical or practical. I hope it is both.
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