Implementation of rapid microwave sintering using a 24 GHz gyrotron system.

Rapid microwave sintering of different oxide ceramics with heating rates up to 300 °C/min and zero hold time has been implemented using a 24 GHz gyrotron-based system for high-temperature processing of materials. The design of the system, principle of operation, and process control are described. Particular attention is given to the design of thermal insulation assemblies and the implementation of temperature measurement in an environment with intense electromagnetic fields.

On the Mechanism of Microwave Flash Sintering of Ceramics.

The results of a study of ultra-rapid (flash) sintering of oxide ceramic materials under microwave heating with high absorbed power per unit volume of material (10-500 W/cm³) are presented. Ceramic samples of various compositions-Al₂O₃; Y₂O₃; MgAl₂O₄; and Yb(LaO)₂O₃-were sintered using a 24 GHz gyrotron system to a density above 0.98-0.

Experimental tests of a 263 GHz gyrotron for spectroscopic applications and diagnostics of various media.

A 263 GHz continuous-wave (CW) gyrotron was developed at the IAP RAS for future applications as a microwave power source in Dynamic Nuclear Polarization / Nuclear magnetic resonance (DNP/NMR) spectrometers. A new experimental facility with a computerized control was built to test this and subsequent gyrotrons. We obtained the maximum CW power up to 1 kW in the 15 kV/0.