I 've been saving all my 6061-T6 scraps for ages. I was planning to do some casting with it, but now that I am getting close I find that 6061 - T6 is reported to be not very good for casting. I wasn't planning to make structural parts out of it or anything, but is there anything I can do with the stuff other than sell it to the recycler for pennies on the pound?
Seems like it has to be formed at pressure and temperature to be of much use.
I've never tried it, but it's supposed to be a fairly good casting material. Why don't you just give it a try?
BTW, the T6 temper has nothing to do with it. Long before you reach melting temperature, the temper is gone and it's indistinguishable from annealed 6061.
chilled as soon as it comes out of the mold and then aged for a while or it's gummy and smears . Aluminum that was cast originally will machine easier right out of the mold but also is harder on (HSS) tooling .
For a pure 6061 casting to be reasonably machinable it needs to be chilled as soon as it comes out of the mold and then aged for a while or it's gummy and smears . Aluminum that was cast originally will machine easier right out of the mold but also is harder on (HSS) tooling .
**************Terry,
I was thinking of pouring thick (1-2") bars and rough round stock for machining for non critical parts. The one video I found that claimed to be casting stock like that from 6061 (thick bars) for machining was cooling a steel mold in a kiddy pool filled with water with an anvil in it for additional heat sinking. Seemed like as soon as it was hard enough to not run out of the mold it went into the pool and boiled off water for a while. I wonder if a super quench solution would cool it down faster, and if it would be a good idea. They had half a dozen bricks cast that you could see at the end of their video, and they looked decent.
Another technique I've read about with fair test results in 6061 seems to be doing something similar. Its called ablation molding where they use a sand mold (or other easily dissolved away mold, and start jetting it away with water when its right at the cusp of going from liquid to solid.
Yeah, Ed.
I was aware the T6 was a designation of its hardening process.
Right, but Bob mentioned T6 a couple of times, and I wanted to be sure that he knew that had nothing to do with 6061's castability.
My local scrap yard is very friendly. If I had a bunch of scrap 6061 I would ask about swapping it for an equal weight of aluminium castings. Your local scrap yard may not be as nice, but it would not hurt to ask.
Dan
Can't get it back to T6 without special treatment , but maybe T4 or T5 ...
The chill and aging both contribute to the hardness of the ingot . Can't get it back to T6 without special treatment , but maybe T4 or T5 ...
********* Seems going from liquid to solid quickly results in smaller grain size. Might have to do some experiments then with cooling speed using water, super quench, and circulated refrigerated super quench. I have very little HSS tooling other than drill bits and a few hand ground lathe bits. Just about all of my mills are carbide, and I tend to reach for carbide insert tools on the lathe except for nasty cuts where the slightly better flex of HSS might survive better.Have to make molds from low carbon steel or they might shatter. That could get interesting. LOL.
A mate works in engine design and development and he has mentioned before that things like cylinder heads are carefully cast so IIRC the main cooling is at the cylinder head face which results in the most beneficial dendrite formation resulting in the highest material properties and as it is critical they also use virgin alloys for those products to ensure the proper metallurgy. Maybe not an issue in your case.
A mate works in engine design and development and he has mentioned before that things like cylinder heads are carefully cast so IIRC the main cooling is at the cylinder head face which results in the most beneficial dendrite formation resulting in the highest material properties and as it is critical they also use virgin alloys for those products to ensure the proper metallurgy. Maybe not an issue in your case.
That's interesting to know. It might also be so the face holds shape and continues to draw metal from the rear as it shrinks and cools. Hemispherical heads are cool, but I suspect not such much for a piston. LOL. Yeah, not super important for what I currently plan to do, but who knows what I might try in the future. I never thought I'd be working in machining when my wife gave me that little toy 7x10 lathe for Christmas 2005 either. Figured I'd die as a communication contractor up in somebody's attic with the wire I was pulling clamped in my teeth in a knock down drag out fight trying to fend off giant mutant rats with a pair of pliers and a razor knife. LOL.
Use Flux for Al. Keep Oxygen out of the hot metal. It will become a sponge of tiny holes.
Float Al Flux over the pour and in the pour bucket as well.
Be sure to use the correct flux.
Mart>
hypochlorite in the melt just before casting to degas the HYDROGEN in the melt . The H2 comes from water vapor coming from the LPG flame I use to melt it . Depending on how much crud is in my feed stock I may also flux for other stuff , but not always . I never float a flux on the melt while pouring . Brass , though is a different matter . I do float a cover of ground glass to prevent oxidation and monitor the temp closely to prevent vaporizing the zinc out of the melt .
So you are saying I should cast on a cold January or in June and July before the humidity moves in for summer.
Yes I did. Depends > >> Use Flux for Al. Keep Oxygen out of the hot metal. It will become
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