Food Science – Why Clean Cast Iron Cookware with Salt?

Copper can be useful for certain tasks due to the its metallic properties (heats quickly, distributes heat evenly, etc.), however I would not call copper pans good "all-purpose" pans.

As for cast iron, you mentioned Le Creuset, and again I would tell you that they are more of a specialty manufacturer. They make some very nice coated cast iron-ware and fantastic large pots, but they're not really the go-to for a simple cast iron pan.

For basic cast iron, go buy a Lodge skillet. They're around $20 depending on size, and will literally last a lifetime. The company has been making these pans for 115 years; they know what they're doing. I use mine 3-4 times per week, and cook almost all my meat in it. It tastes better after every use.

Aluminum is easy to CNC mill and it can be make non-stick

It needs to be finished to a semi-gloss, and have a slightly undulating (smooth wave pattern) surface to allow for release

It should be hard-anodized to reduce surface pores and future oxidation. Do not scrub hard-anodized surfaces, just soak

Cast aluminum will most likely have too many surface pores to me useful