Aluminum Wire For Casting

[hardware1170]

I'm sure this is in the forum somewhere, I must be searching the wrong thing. Is aluminum service cable good quality aluminum to melt for casting?

 

[John Hasler]

Aluminum electrical wire is nearly pure aluminum. It is optimized for conductivity at the price of mechanical properties. It might not cast well. Maybe dilute it 10:1 with scrap castings?

 

[RJSakowski]

As I recall, aluminum used in casting usually has a high percentage of silicon to reduce surface tension and increase fluidity which give better filling of the mold. Other alloying metals are present as well. Electrical aluminum is almost pure aluminum and won't cast and/or machine as well.

A better source would be old castings such as small engine blocks, etc.

 

[RJSakowski]

Years ago, I had seen a foundry supply house that sold silicon billets for adding to aluminum. The percentage of silicon in cast aluminum typically runs in the 1.5 - 3% range. It would be conceivable to make your own alloy using the electrical grade aluminum and adding appropriate amounts of alloying metals. It would be painfully laborious but you could harvest silicon from old semiconductors. Some of the power transistors and thyristors have fairly large chunks.

 

[hman]

Would that produce P-type or N-type aluminum????

PS - wild idea - if you live near a semiconductor manufacturer, maybe you could talk them out of some scrap wafers. Of course, you'd have to grind up the silicon to get it to dissolve/alloy efficiently. But that's not too difficult, as it's nicely brittle. A mortar and pestle could work well.

 

[chips&more]

Would that produce P-type or N-type aluminum????

PS - wild idea - if you live near a semiconductor manufacturer, maybe you could talk them out of some scrap wafers. Of course, you'd have to grind up the silicon to get it to dissolve/alloy efficiently. But that's not too difficult, as it's nicely brittle. A mortar and pestle could work well.

LOL!
PS, a wild idea indeed! Even @ 1%

 

[chubbyjp77]

The other problem, besides alloy, with wire is surface area. You'll likely get a lot of dross.

 

[RJSakowski]

It appears that the dopants used to make n or p type silicon are on the order of .01% or less. I would expect that they would not materially affect the alloy.

Re: surface area, the Backyard Foundry suggests forming a pool of molten aluminum first and then pushing the fresh aluminum below the surface. I have melted down .o63 sheet scrap in this manner.