Microwavable Metals

I don't know exactly..i think that you can't use any metal..but for god's shake don't try anything without knowing ..exept the case of wanting to bomb your house.....

Thank you for your response, however, I have a project that I'm about to start, and I need to know the materials that are being tested and used in microwave ovens for cooking that contain a composite material. What I do know is that there are metals and plastics being combined to allow the microwaves to pass through the material. What I don't know is what materials are being used, and if so, can they be used under pressure?

I know of glass ware that incorporates metal oxides to aid in browning meet. But no metal objects that are not an inclusive part of the original design can be used.

What kind of project are you doing? Will you be microwaving composites yourself? Why do you want to do it under pressure? These kinds of details are necessary for a proper response to your question.

That said, I know that at some universities, microwave ovens have been used to sinter metal powders or ceramics. Years ago, there was a lot of effort into creating microwaveable TV dinner packaging that concentrated microwaves to provide browning and more even heating of the contents; these packages used metals as a shield or microwave concentrator (antenna of sorts).

The references in these patents may be useful to you. Try a Google Scholar search yourself too.

http://www.google.com/patents?hl=en&lr=&vid=USPAT4641005&id=ffksAAAAEBAJ&oi=fnd&dq=microwave+metals

http://www.google.com/patents?vid=USPAT5568765

Thank you for the information.

I know that if you have metal such as the pie pans. If it is inside another container, it will not arc. I accidentally did this when microwaving my lunch one day. I left the aluminum foil on a burger and nuked it when it was in a small plastic dish and to my surprise it didn't pop or arc or burn the metal in any way. After that I wanted to see what I could get away with so I found success with metal inside a cardboard container. I do not know of a metal that can be put directly in front of the micro-waves. You may want to research convection ovens, they are both a normal oven and microwave but the inside is bare metal.

I don't understand the question, at least it is not complete.

The casing of a microwave oven is full metal, to keep the microwaves in.

The aluminium metal food boxes can be put in a microwave oven, but don't expect the waves to go through.

Lead containing ceramics get hot (could be that other stuff also heats up)

Typically small metal parts form a problem as they might act as an antenna, harvesting the energy. (metal decorations of plates start to arc)

"759. Why do metal objects spark/arc in the microwave? Why don't the metal walls of the microwave spark? - JR Like all electromagnetic waves, microwaves are composed of electric and magnetic fields. Since an electric field exerts forces on charged particles, a microwave pushes electrons back and forth through any metals it encounters. It is this motion of electrons back and forth through the metal walls of the microwave oven that allow that metal to reflect the microwaves and keep them inside the oven. If you leave a spoon in your cup of coffee as you heat it in the microwave, electrons will move back and forth through the spoon. This motion of charge will cause no problems so long as (1) the spoon can tolerate this flow of charge without overheating and (2) the spoon doesn't allow the charges at its ends to leap into the air as a spark. To keep the spoon from overheating, it must be a good conductor of electricity. Since most spoons are pretty thick, the modest currents flowing through them in the microwave will leave little energy inside them and they won't overheat. But a thin twist-tie or small bit of aluminum foil may well overheat and begin to burn. To keep the spoon from sparking, it should have smooth ends. Electrons are more likely to leave the end of a metal surface at a sharp point, so avoiding points is important. Most spoons are smooth enough that no sparks will occur. But a fork, a sharp piece of foil, or a twist-tie may well begin to emit electrons into the air as those electrons pile up at one end of the wire while the microwave oven is on. Like a spoon, the walls of the oven are good conductors of electricity and they have no sharp points. While electrons move back and forth in these walls, they simply reflect the microwaves without becoming very hot and without emitting any sparks. You'll note that the light bulb for the microwave is always outside the cooking chamber because it contains small bits of metal that would have trouble inside a microwave oven. 724. Why is it bad to put metal in a microwave oven? - OR It isn't necessarily bad to put metal in a microwave oven, but it can cause cooking problems or other trouble. Microwaves cause currents to flow in metals. In a thick piece of metal, these currents won't cause problems for the metal. However, in thin pieces of metal, the currents may heat the metal hot enough to cause a fire. Metallic decorations on fine porcelain tend to become hot enough to damage the porcelain. But even thick pieces of metal can cause problems because they tend to reflect the microwaves. That may cause cooking problems for the food nearby. For example, a potato wrapped in aluminum foil won't cook at all in a microwave oven because the foil will reflect the microwaves. The currents flowing in the metal can also produce sparks, particularly at sharp points, and these sparks can cause fires. In general, smooth and thick metallic objects such as spoons aren't a problem, but sharp or thin metallic objects such as pins or metal twist-ties are."

The above was from a microwave website. It is true as best I know, but I do not recommend trying it.

Thank you for the informantion.

Any metal can be used in a microwave oven...

However, the parts must have rounded edges and be shaped to keep a seperation from the oven walls etc... This is to avoid breakdown of the dielectric, air in this case.

Also the metal parts must obviously be flat to prevent shielding the food requiring cooking...

My combination microwave oven I've used for 12 years came with metal accessories to use, it works great!!

So I guess that answers your question, I think?!

John.

Hi John ,

I would have said metal is OK , but ;

No angles - to prevent arcing

Bulky - to minimize current.

Thats probably the same , except thin is not good if extreme. If you want to dice with death and explosion try a piece of paper backed cigarette foil - It will combust explosively. Yes , I have tried it , and my oven survived the spectacular result of a 2 or 3 cm² piece of foil.

I can't really think why anybody would need to use metal nowadays , so I agree with you John - you can use metal , but no you shouldn't (!). 12 years is impressive - Not sure why , but I would have expected the magnetron to have failed by now. Kris

I have heard that if you can't put a lipstick into a microwave oven because it contains some metals ...Is this real?

If you remove the decorations (necklace and earrings, piercings and other stuff) it is not that dangerous. Of coarse you need to have a big microwave oven, as you need to close the door before it works.

Only the glitter ones.

For your safety, don't put your wife's platinum-rimmed, china, coffee cup in a microwave!

In 1992 i was working in a develomental die shop in West Virginia for a major steel producer. One of the product we were working on was a microwavable tin can. It worked, it was a regular tin plate with an organic coating ( same as used today inside food cans)inside and out. The catch was getting the correct geometry for effiecent and even heating of the product. I have microwaved several of these cans doing heating test with out any problems or adverse affect to the ovens.

What happens when you microwave one of these cans when it is sealed shut?

'jwgri' may be missing letters and jumbled for a reason.

What happens when you microwave one of these cans when it is sealed shut?

We always opened the double triple fold safety end ( another story) we used on the cans before they were put into the microwave, although it might have been interesting to try it with the end intact.