High Copper Alloys- Lets discuss this further

[357maximum]

THANKS....Buddy!!!!!! Can't stand it I am retired and can play at will, can you?!!!!!!!!!!!!!!

Edd

Here I am trying to help a feller out and I get accused of jealousy, what has this world come to. I am offended Looks to me like you waste alot of that time thinking anyway, that is not good for you ya know, you might start losing your hair...oh wait

[runfiverun]

okay this is something new.
i have alway seen the antimony and copper nearly equaling the tin.
because the tin would help keep the copper in solution better.
i still don't know if the copper bonds with the antimony even with the tin chain between/binding them.
otherwise you'd have a PbSbSnCu chain rather than a PbSnSbCu chain.
all of your tin would be pulled to the antimony in the first one allowing the copper to become a free molecule [this could explain the alloys fluidity]
the second would bond the tin to the antimony, and the tin and the copper causing a semi strengthening SnCu chain, free from the SbSn chain.
basically we know what normally happens to free tin in an alloy but this way it would have the copper with it.

the only other thing i can think of is the SnCu is binding in between and to the Sb molecules allowing them to move and glide.
and be more distributed throughout the alloy.
acting much like adding Pb to a CuSn alloy does.

this might explain the expansion thing too as everything goes about it's business getting in place.
shrug...

[357maximum]

Is it more important to know:

1.THAT IT WORKS
2. Why it works

I'll shrug too

[303Guy]

I remembered something - my copper enriched alloy exibeted soft and hard bands. I thought it likely to be caused be the way the mold was filling up.

This should show what I mean
These are worst examples.

I used flawed castings for test tube firing since no accuracy was required.

I had one boolit twisting along a plane which I think became fluid as it expanded into the case mouth - chamber gap. The casting flaw/soft area happened to align with the gap.

Here it is

[303Guy]

Is it more important to know:

1.THAT IT WORKS
2. Why it works

I'll shrug too

Being the curious sort, it's hard call!

[badgeredd]

Chkor

[45 2.1]

I feel we need to understand the mechanics of the alloy to take full advantage of using it. We know the mechanical properties of the Cu enriched alloy is an improvement when trying to go fast but if we understand somewhat why, we might figure out other ways to further improve the alloys. Edd

I'll try to help here. Does anyone know why factory jacketed bullets have the core alloy they do and what it is? Depending on who and what you read, most seem to have about 2% antimony with little tin. Those factory cores are swagged, then put in a jacket and re-swagged. I have a good quantity of old cores.... BHN about 7 to 8. If you harden them up, as the factory did for some of their premium hunting bullets, they don't shoot as accurately. That is where I got the idea to cut COWW alloy hardeners down.... ie to make the antimony a lower % content. That all by itself increased accuracy potential greatly over straight WW. If I added too much tin, the accuracy fell off some. Heat treatment with more tin did not help matters either. As you know a lead/tin alloy will not age harden. An antimony based alloy will age harden due to the lattice structure antimony produces. From these experiments I cut tin out of my alloys and good things happened with harder boolits. I will have to assume that copper also grows a lattice structure as most folks here say it grows in diameter along with some hardness spurts. Maybe too much tin isn't the best thing.........

[Hardcast416taylor]

DUH!!! I`ve been trying to follow this discussion and try experiments of my own making for hardness and balance of alloys. I can only say that I have the mental abilities of a plumber, that ability is remembering that the hot water lines go on the left side of a faucet. About the most I remember of my chemistry classes in HS and college is HOW to spell CHEMISTRY! I do look forward to what is finally determined here as a good H.V. alloy that even I can attempt to make up correctly. Robert

[kbstenberg]

Questions and observations from a student.
Because YOU are working with a new type of alloy (copper added) shouldn't the properties and performance of the bullets be different? You start with known information from a lead projectile. Then change what to expect in performance and method of manufacture to the properties of the new alloy. Which at this point the book is continually being changed till you find the correct combinations to accomplish the goal.
I haven't mixed any alloy yet. When you are planning what weights of the components ( COWW, SOWW, Superhard, Lino, Copper) do you use one of the lead calculators and keep changing the weights of the components till you get the percentages for the alloy that you want? When I look at Bumpo's calculator it lists all of the different components and what they generally are made of. Are you guys using those figures as the chemical base for your alloy? Kevin
Robert weren't you and I in the same Chem. class!!

[Jailer]

r5r,

I'm glad someone else thinks that the intermetallic compounds might explain this extended hardening period. You said it better than I but that is exactly what I've been wondering/thinking. Like I said earlier, it appears to me the only way we'll get an answer is to try using both versions of the alloy in side by side tests with the only thing that is different is how we balance the alloy.


Edd

The intermetallic compounds would also explain why they continue to grow slowly over time. I was reading a paper last night that was researching this phenomenon as it applies to soldered joints. The microstructure at the intermetallic bond between the two parts that were joined continued to slowly grow and significantly increased the mechanical bond between the two parts joined.

[btroj]

I found a paper that discussed how pour temp can change which intermettalics form. Makes me wonder if those change slowly over time based upon ambient temp and this is why the long period to stabilize?
In the end we may not have the ability to totally understand WHY something happens. I am happy enough to know WHAT happens. Knowing what to expect, when to expect it, and how to deal with its good enough to me.

[303Guy]

NOW my head hurts!
Could you explain it a bit please? What do those lines mean? Would it be a safe starting point to have equal amounts of each? How would adding lead affect the mix?

I guess we are going to need to determine the range of constituents that will work for us. To get exact amounts is quite difficult with scrap metal, the only constituent we can be sure of is the lead itself since we can get SOWW and lead pipe. If we know how much copper we want to add we can weigh the right size piece and dissolve it in. We can get high tin from pewter and ignore the other bits in it. But antimony is a problem to me. So far I have quite a nice high tin alloy with some unknown copper in it but even the tin amount is not accurately known since I was adding raw drain pipe (not set up to smelt yet). I need a source of antimony.

[Jailer]

I've been playing around with an alloy calculator and I'm running into the same problem. I can't get the Sb level high enough to balance out with the material I have on hand. I wish I would have known this when I ordered the supertough, I would have added in a pound or two of superhard.

[runfiverun]

but what happens when lead is present.
that adds one more b into the equasion.
plus it's the majority so there is enough room for everything to "find" it's place.
tin is trying to go to the outside allowing the Sb to break through to the surface in a normal alloy.
is the Cu going with the Sn or is it matrixed with the Sb.
if it's the Sb then the Pb is also in the mix and the copper is staying inside the boolit if it's going with the SbSn it's trying to get to the outside.
any free Sn is gonna cause hard spots on the surface unless it has something else with it.

so has anybody seen dark spots on their boolits with the extra tin alloys when using copper?
was it more than a 3 to 1 mix of tin to copper?
was it after a 50-50 mix of tin with antimony.
anyway it is looking like this is gonna come down to tin/no tin.
this will mean that close observation and reports are gonna have to be made so direct comparisons can be done.
a small window of focus [volume/percentage,whatever] is the only way to determine what affect the tin will have.

[btroj]

Ok Run, while I appreciate your input here don't you have lube to make and test? All this alloy stuff is just taking you away from assigned duties.
Now be a nice gent and be back to making new lines for us, please?

I need to order some Babbitt from Rotometals and wait for the results of the testing I sent off. I want to see what my monotype really has in it rather than assume.

In the end it looks like we may need to try some different mixes and see what they do over time.

[badgeredd]

Bmizgd

[badgeredd]

Gdboyz

[Jailer]

The alloy calculator I'm using assumes 3% Sb for COWW. You did send me a recipe but it comes up short on Sb with the 3% assumption. This is what I end up with.



Who knows, maybe I should just mix it up and try and see what happens.....

[kbstenberg]

Jailer What was the given BHN for the above alloy?

[Jailer]

12.2 is what it calculated it to be.