Microwave Technique: A Powerful Tool for Sintering Ceramic Materials

摘要

Microwave sintering has emerged in recent years as a promising technology for faster, cheaper and eco-friendlier processing of a wide variety of materials, which are regarded as significant advantages against conventional sintering procedures. The present investigation describes a technique for sintering two different ceramic materials by microwave heating: alumina-15vol.% zirconia and hydroxyapatite nanopowders. The results show that microwave sintering achieves higher density values, excellent mechanical properties and a homogeneous microstructure at lower sintering temperatures. The densities of microwave processed samples were close to the theoretical densities, and the near-net-shape of the green body was preserved without significant dimensional changes. The main advantages of microwave heating can be summarized as follows: a more flexible process, reduced processing times and production costs, and environmental benefits. Thus, microwaves are a clear alternative to conventional heating methods, using up to 70% less energy through-out the whole sintering process.