MODELLING AND SIMULATION OF MICROWAVE METAL INTERACTION AND ITS VALIDATION

Abstract

Microwave energy has been in use for variety of applications for over 8 decades(during second world war). These applications include communication, food processing, wood drying, rubber vulcanization, medical therapy, polymers, etc. In the last two decades microwave heating has also been applied very effectively and efficiently to heat and sinter ceramic materials. Microwave heating is recognized for its various advantages, such as: time and energy saving, very rapid heating rates, considerably reduced processing cycle time, fine microstructures and improved mechanical properties, better product performance, etc. The most recent application of microwaves has been in the field of metallic materials for sintering, brazing/joining and melting, a surprising application, in view of the fact that bulk metals reflect microwaves. However, reflection by a metal occurs only if it is in a solid, nonporous form and is exposed to microwaves at room temperature. Metals, in the form of powder, however absorb microwaves at room temperature and will be heated very effectively and rapidly. Several common steel compositions, pure metals and refractory metals have been sintered in microwaves to nearly full density with improved mechanical properties. A new method of heating called Microwave hybrid heating was developed by coupling the principles of microwave and conventional heating, and it is employed successfully in the joining of bulk metallic materials like bulk copper , bulk stainless steel (SS-316) and joining dissimilar metals like Mild steel- stainless steel joints. However to understand the mechanism, sensitiveness of the parameters and for better understanding of the process it needs to be simulated.