Review Microwave Processing of Materials : Part I

Microwave processing of materials is a relatively new technology alternative that provides new approaches for enhancing material properties as well as economic advantages through energy savings and accelerated product development. This paper presents a state-of-the-art review of microwave technologies, processing methods and industrial applications. The characteristics of microwave interactions with materials are outlined together with the challenges to process materials that are difficult to process with conventional methods. Clearly, advantages in utilising microwave technologies for processing materials include penetrating radiation, controlled electric field distributions, rapid heating, self-limiting reactions, and selective and volumetric heating. The aim of the work presented in this paper is to help guide those interested in using microwaves to improve current materials processing. Microwave fundamentals are described to provide a brief awareness of the advantages and limitations of microwaves in the processing of materials. Furthermore, the limitations in current understanding are included as a guide for potential users and for future research and development activities. Examples of successful applications in the United States of America (USA) and Australia are given to illustrate the characteristics of materials, equipment and processing methods applicable to industrial microwaves.