Yes, your pie iron can be saved! Hitchiker gave some good advice about heating it in a fire. I use our gas grill.
First, wash the iron with hot water and steel wool--use no soap--to remove the rust. The heat from the hot water should be enough to dry it. Next, put a light coat of Crisco all over it, inside and out. Place on your grill and close the lid. Turn the burner(s) up to medium and let it set there for about an hour. Turn off burner and let cool. Remove from grill.
Don't forget to remove the wood handles before all this!
After each use, clean with hot water--no soap and no steel wool. Re grease and reheat.
Over time, the inside should get a nice black coating on it. This is what makes it a non-stick utensil.
And, yes, there are both cast iron and aluminum pie irons. Here's a website for Rome Pie Irons: http://www.romeindustries.com/aboutpieirons.htm