The best non-absorbent materials for microwave ovens are those that reflect microwave radiation rather than absorbing it. Here are some commonly used materials that are suitable for constructing microwave ovens:
Stainless steel: Stainless steel is a popular choice for the interior of microwave ovens because it is highly reflective to microwaves. It helps to distribute the microwaves evenly throughout the cooking chamber and prevents them from escaping.
Aluminum: Aluminum is another metal that has good reflectivity to microwaves. It is often used as a secondary material or in combination with stainless steel to enhance the reflection of microwaves.
Copper: Copper has excellent electrical conductivity and can reflect microwaves effectively. However, it is less commonly used in microwave ovens due to its higher cost compared to stainless steel and aluminum.
Metal mesh screens: Some microwave ovens use metal mesh screens on the door or vents. These screens are typically made of materials like aluminum or stainless steel and allow for visibility and ventilation while still reflecting microwaves.
It's important to note that these materials are typically used for the interior walls and components of the microwave oven rather than the external housing. The external housing of a microwave oven is often made of non-metal materials such as plastic, which do not interfere with the microwave function.
When purchasing a microwave oven, ensure that it is constructed with materials designed for microwave use, as improper materials can result in safety hazards or inefficient cooking.