Aluminum foil is exactly what it sounds like, which is to say, aluminum that has been shaped into a thin sheet via either rolling or some other process. This is possible because aluminum is a malleable metal, which is relevant because the more malleable that a metal happens to be, the thinner the sheet that can be produced through such processes. Previous to the invention of aluminum foil, tin foil saw use for similar purposes but ended up being supplanted because it wasn’t quite as good, which is why there are still people who call aluminum foil by the rather misleading number of tin foil.
Regardless, the important takeaway is that aluminum foil is actually made of aluminum. It is interesting to note that it is sometimes laminated with either paper or plastic to make it useful, but for the most part, aluminum foil is made out of aluminum. As a result, this means that the aluminum in aluminum foil can be recovered to be made into other things as well, as shown by a recent video of a Japanese knife-maker who turned a roll of aluminum foil into a fully-functional knife.
How Well Would an Aluminum Knife Perform?
Of course, there are reasons why aluminum isn’t used as a common material for knives. In short, the same malleability that makes aluminum suitable for use as aluminum foil means that it isn’t a particularly strong and long-lasting material. As a result, while it has a number of useful characteristics such as its corrosion resistance and its lightweight nature, it has a harder time retaining an edge suitable for use. In fact, this is the reason that aluminum tends to be combined with other metals to create alloys when put to practical use save in cases when malleability is the primary point. Still, whether it is practical or not, the Japanese knife-maker’s achievement is certainly a very interesting demonstration of their chosen profession.