Electromagnetic Mechanism for Microwave Heating of Powdered Metals

Jirun Luo, Christian Hunyar, Lambert Feher, Guido Link, Manfred Thumm, Paola Pozzo

Forschungszentrum Karlsruhe, Institut für Hochleistungsimpuls- und Mikrowellentechnik, Postfach 3640, 76021 Karlsruhe, Germany

The full sintering of powdered metals in multimode microwave system supports the speculation that the power losses are mainly caused through magnetic induction heating, but experimental proof has some difficulties because the electric field and the magnetic field cannot be fixed in the system. This article will, starting from the fact that the electric field is not zero in a conductor with finite electric conductivity, physically explain it mainly as the result of magnetic field losses. And an interaction model has been established to study the physical process of microwave heating of powdered metals, which has shown good uniformity with the experiments presented by the articles [1,2].

[1] R. Roy et al., “Full sintering of powdered- metal bodies in a microwave field”, Nature Vol. 399, P668, June 17, 1999.

[2] J. Cheng et al, “Experimental proof of major role of magnetic field losses in microwave heating of metal and metallic composites”, J. Mats. Sci. Lett. Vol. 20, P1561-1563”, 2001