You can. In fact, it's a fun alternative to fireworks when the weather is bad outdoors. NO NO NO NO NO!!!! NEVER microwave metal. It will create an arc which can ruin the microwave, or even start a fire in whatever else is being mic'd. My MIL did it just the other day, and it was only a wire twist tie on a bread wrapper. Caught the wrapper on fire and ruined the bread. If she hadn't been standing right there, it would have ruined a brand-new over-the-range microwave.
Your microwave oven's case is made of metal, and so is the microwave waveguide. Explaining why you can't stick a piece of metal on a microwave oven turntable is technically complicated, but what' you're basically doing amounts to the same thing as the loud squeal you hear at a concert where there is audio feedback.
Putting a piece of metal in a microwave oven acts like a wave mirror and you're causing feedback to the system which is usually fatal to the system. Anything exploding would be similar to ripping your speakers apart with the audio feedback.
I've done it before, not on purpose... Had a twisty tie on something I was cooking. Did not notice it when I put the food in. Even with that little amount of metal there was a lot of "excitement" going on in my micro way - lucky I did not leave the area and notice it within a couple of seconds. I highly recommend you DO NOT try it.
A microwave works by resisting electricity and creating heat from that, much like a toaster, when an electricity conductor is inside a microwave, while it is resisting the electricity to produce heat, that electricity is being attracted to the metal, making it hot and creating sparks.
1 year ago
Last edited at 7:39AM on 3/27/2012
(PART 1) Microwave ovens use microwaves to heat food. Microwaves are radio waves. In the case of microwave ovens, the commonly used radio wave frequency is roughly 2,500 megahertz (2.5 gigahertz). Radio waves in this frequency range have an interesting property: Water, fats and sugars absorb them. When absorbed they're converted directly into atomic motion -- heat. Microwaves in this frequency range have another interesting property: Most plastics, glass or ceramics don't absorb them. But what about metal?
The walls inside a microwave oven are actually made of metal. It turns out that a fairly thick piece of metal works a lot like a mirror. But instead of reflecting an image, it reflects microwaves. If you were to put food in a heavy metal pan and put it in the microwave, it wouldn't cook. The pan would shield the food from the microwaves, so the food would never heat up.
1 year ago
Last edited at 7:54AM on 3/27/2012
(Part 2) Tiny sharp pieces and thin pieces of metal are a different story. The electric fields in microwaves cause currents of electricity to flow through metal. Substantial pieces of metal, like the walls of a microwave oven, can usually tolerate these currents without any problems. However, thin pieces of metal, like aluminum foil, are overwhelmed by these currents and heat up very quickly. So quickly in fact, that they can cause a fire. Plus, if the foil is crinkled so that it forms any sharp edges, the electrical current running through the foil will cause sparks. If these sparks hit something else in the oven, perhaps a piece of wax paper, you'll probably be reaching for the fire extinguisher.
While it's highly unlikely that a small piece of foil is going to cause your microwave oven to totally explode, it could cause a fire. So, it's a good idea to stick to plastic wrap, paper towels and any other non-metal kitchen aids.
In short you can and you can't at the same time. You can when it has thick and rounded edges. You can’t when it has thin and/or sharp edges.
because metal is conductive, and there is a bunch of MICRO electricity waves that arent visible to the naked eye that move around in there. Also, the rays are ultra violent and pass through thin matter.