文摘
Microwave sintering has emerged in recent years as a non-conventional method for sintering materials with significant advantages against conventional procedures. By microwave sintering are achieved higher density (~99%), hardness (18 GPa) and fracture toughness (6.3 M Pam1/2) properties and homogeneous micro-structure compared to conventional heating. Reason why, the design of microwave systems, including adaptive control schemes, becomes a very important topic to be performed. The present work describes the microwave cavity control system design for sintering alumina-zirconia nanocomposite. The samples were sintered in a multimode microwave furnace (2.45 GHz) at different temperatures (1200-1400 °C) in air. The main challenge from the control point of view is to guarantee an small tracking error, when a temperature profile is required, due to the nonlinear dynamical behaviour of nanocompistes.