There is no need for it....cast iron distributes heat very well.
But...cast iron is cast...not rolled...and cast copper and aluminum would have to be cast too....and I don't believe the 2 could be fused.
Linda C

The most common complaint that I see from people using two burner cast iron griddles is that there are hot/cold spots. This makes intuitive sense since there is probably 6"+ between the outsides of the burners.
Seeing this sort of complaint I immediately wonder why we don't see a solution similar to that used on steel (rest aside that steel is rolled)
I also believe that the two cannot be fused. Otherwise I
believe that it would be available.

Lindac is wrong about pretty much everything. Compared with copper or aluminum, CI is a poor conductor. Heat-wise, it is slow and spotty. Don't know specifically about its mating characteristics with aluminum or copper but strongly suspect it can be mated with other materials as readily as anything else. (they do it with stainless steel, for example) However, since it is first cast with a thickness sufficient to maintain its own integrity -- rather thicker than rolled materials used in other pans -- adding an aluminum or copper bottom would gain nothing in conduction/transmission (actually would lose a little) and little in distribution. Expansion coefficients would be more troublesome to manage than with thinner materials or materials with more closely matched conduction characteristics. It would also become even heavier than it already is.

Reminds me about some sort of science TV program from long ago.They cast a small frying pan using gold instead of iron to demonstrate heat conduction. They had Julia Child fry eggs in it. She agreed it was much superior except the handle got very hot very fast and the weight was "a bit of a problem at my age".

Given what they charge for regular pans today, I've sometimes thought maybe there was some gold in there.

National geographic had something like that as a portion of an article they did on gold many years ago. As I recall, the performance with eggs was enviable. The object was to demonstrate its superior conductive properties.

See, now that is what I'm talking about. If heat conduction is superior in a small pan, how useful would a boost be across a two burner griddle which has a big indirectly heated gap between the burners?

Also, the weight of FE=26, AU=79, so a 20lb iron griddle would have to weight 60lbs in gold!

Oooo....I want one!

Copper is a BETTER conductor of heat than Gold.

There is more to it than just conductivity. Cross sectional area of conductor determines HOW MUCH heat is to be moved from hot side to cold side as well. This is why heavy clad is better than thin plate.

I make copper bottom cast iron pans, griddles etc for friends and family. They are most certainly NOT EASY to make PROPELRY. The process would be very costly for a commercial venture.

Not to make you jealous, but, I will say they are amazing...no hot spots/cold spots and warm up much more quickly and evenly.

Jamoke, can we talk you into describing how you go about making such items? Since you're not doing this as a commercial venture, I don't imagine it's trade secret or anything like that. I'm quite curious to learn about this.

Thanks!
--Solar