castting

I am research student I need any one interest in casting of copper base all oy 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 chr ome 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 wit h mechanical properties, corrosion and wear resistance. Please if you any o ne 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

Reply to
asaadka77
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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.

Reply to
David Billington

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.

Reply to
Tim Wescott

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.

Reply to
Tim Wescott

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.

Reply to
David Billington

Phase Diagram:

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It shows how the solubility of chromium in molten copper increases with temperature.

Eutectic:

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-jsw

Reply to
Jim Wilkins

Copper and chromium are not miscable, but they are somewhat soluble, and th ere is a whole class of copper/chromium alloys:

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When the alloy is cooled, the chromium either goes into solid solution (fas t quench) or it precipitates out (slow quench). The usefulness of the alloy depends upon further heat treatment, which allows a fine matrix of chromiu m to precipitate out of the alpha copper, resulting in a very strong, preci pitation-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 Soc iety for Metals. I can look it up but it's worthwhile for the OP to make hi mself familiar with the resources. This is pretty obscure stuff and you hav e to find your way around the basic references if you're going to get anywh ere with complex and obscure questions such as these.

Reply to
edhuntress2

Copper and chromium are not miscable, but they are somewhat soluble, and there is a whole class of copper/chromium alloys:

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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.

Reply to
Jim Wilkins

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.

Reply to
edhuntress2

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

Reply to
Asaad Kadhem

Thank Mr. Tim Wescotti ....research and read more papers ...but some of problem in practice or some things can not be includedcan in papers

Reply to
Asaad Kadhem

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

Reply to
Asaad Kadhem

ome one who is expert in casting in the workshops because in practice the m elt 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 alumino thermic reaction (like thermite).

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

Reply to
edhuntress2

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

Reply to
etpm

some one who is expert in casting in the workshops because in practice the melt and cast very difficult

That's good advice -- he really needs to know which questions to ask -- but , as one who covered materials, including casting, in the metalworking pres s for 40 years, I would be very surprised if he finds answers to his specif ic questions in any ordinary casting book.

I doubt if chromium/copper alloys are cooked up in any ordinary casting ope ration. It's a specialty and the only people who are likely to know about i t 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 ass ociations who know the highest-level engineers in the field I'm inquiring a bout. 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 (for merly the American Society for Metals), and the ICA (the International Copp er Association). Here are their websites:

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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 stu dents and educational institutions. They're the most likely places to reach someone who really knows the answers.

Reply to
edhuntress2

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

Reply to
etpm

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

Reply to
rangerssuck

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