This RUI award by the Division of Materials Research to Pennsylvania State University at University Park addresses two questions: first, how metal powder compacts are heated so efficiently by microwave radiation and, second, if the initial stage of sintering fits conventional models or does the explanation require a microwave-specific model? These two questions will be addressed by Professor Zimmerman and the team at Pennsylvania State University at Altoona on three fronts: (a) an empirical study of the complex permittivity and permeability of powder metal compacts as a function of temperature, particle size, particle oxidation, and packing density using resonant cavity techniques; (b) identification of the separate contributions of the electric and magnetic fields to the heating and sintering using a single-mode microwave system; and (c) evaluation of the first stage of sintering by direct examination of heated (sintered) samples by inspection with both optical and scanning or transmission electron microscopy (SEM or TEM). The focus will be on transition metal powders of copper, gold, and tungsten and ferromagnetic powders of iron and cobalt, due to the industrial significance of these materials. The knowledge of the temperature distribution and energy deposition gained from these present studies would advance understanding of the microwave sintering process.
This project would provide new knowledge on the electromagnetic properties and microwave heating and sintering of powdered metals, which could have wide applications in industry. In addition, the project includes training and development of students and enables professional development of faculty and a postdoctoral researcher. This work is in a research environment for undergraduate students who are preparing for graduate studies or industrial work in the applied sciences and engineering. The universities B.S. degrees in Science, Electromechanical Engineering Technology and a proposed degree program in Applied Science of Materials will benefit greatly from this undergraduate research program. The students will reap educational benefits while making significant contributions to the success of the research. Their experience will culminate in the dissemination of results with oral and poster presentations at regional or national meetings. The studies complement work at the Materials Research Institute at Penn State University in University Park and the undergraduate students will benefit from an exchange of ideas with other students, post- doctoral researchers, and faculty at Penn State University in University Park.
