You can dyesub onto aluminium sheet, or glass for that matter, as long as the substrate is coated.
The answer from Webtrekker seems to be the most relevant answer to the original question since full color printing on metal is mostly what is being advertised on the Internet and TV these days.
If you're not equipped for sublimation currently, contact Sawgrass or another vendor that makes sublimation equipment, or any one of the many distributors that sell sublimation ink and other supplies. They can guide you.
There are also a number of trade printers that offer this capability. Check with whoever you use for your full color non-apparel printing.
If you're just looking for a 1-up or limited quantity, set-up an account with one of the online print-on-demand services like Zazzle, Society6, etc.