MICROWAVE HEATING SIMULATION OF METALS AND DIELECTRIC CERAMICS

The research objectives proposed to study metal processing using a modular industrial microwave oven. The intent of the oven was to perform casting for metal processing purposes. The research objectives were to validate the ovens performance for melting copper and then to compare the results to modeling data. The initial intent was to test the oven for its capability to melt metals. Most researchers would argue that the industrial microwave could not be used for metal processing. However, this research proposed to answer the question as to whether the industrial microwave oven could be used for processing metals or not. The strength of the research lies in the fact that the technology had not been tested on a global scale and industry has not accepted the capabilities of the oven. Nevertheless, developmental efforts have continued and the microwave technology has not ceased to be developed. Although there would be problematic issues, the focus was not to prove the theoretical equations and derive large data sets for the experiments; but to validate that the oven could be used for processing metals and used in an industrial setting where alternative metal processing technologies exist. In order to perform the research, the unit was designed and manufactured and auxiliary components purchased. The research proposed to cast copper in the experimental modular microwave oven and compare the data to the modeling data. Data collection was basically coordinated using thermocouples along the mold and an optical pyrometer for the metal. The final casts were analyzed for both metallurgical and chemical characteristics. A model was designed based upon the dimensions and operational parameters of the experimental oven and data comparison was made. A simulator was then derived using computer code to formulate a user interface panel and simulation environment representative of a laboratory environment.

In order to pursue the research goals, material properties were derived as functions of temperature. For the electromagnetic properties the dielectric permittivity was required along with suggestions for the electromagnetic boundary conditions. An experiment was developed and the properties were measured for several dielectric materials; thus the most suitable ceramic material chosen.