Advanced Ceramic Materials Sintered by Microwave Technology

Abstract

Processing of ceramic materials has also a strong impact in the quality of the consolidated body, as it plays a key role in the resulting microstructure and, as a consequence, in its final properties. Advanced ceramic materials are commonly processed as powders and densified via a high-temperature process. Traditional processing techniques include hot isostatic pressing, mold casting, and sintering in conventional ovens. As ceramics require very high processing temperatures compared to metals and polymers, these processes tend to be very energy intensive and result in higher production costs to the manufacturers. Therefore, new technologies known as nonconventional sintering techniques, such as microwave technology, are being developed in order to reduce energy consumption, while maintaining or even improving the characteristics of the resulting ceramic material. This novel and innovative technology aims at helping industrial sectors lower their production costs and, at the same time, lessen their environmental impact. On the other hand, it is interesting and necessary to know and explore the basic principles of microwaves to advance in the development of materials that demand, every day more, the different industrial sectors. This chapter presents the most recent advances of two materials with a great industrial future: zirconia and lithium aluminosilicate.

Review on Energy Efficiency Progresses, Technologies and Strategies in the Ceramic Sector Focusing on Waste Heat Recovery

“…[ 16,41,[91][92][93][94][95][96][97][98][99][100][101][102][103][104] Application of state-of-the-art technologies Study on the application of energy efficiency technologies in the case of the ceramic plants. [105][106][107][108][109][110][111] Analysis of flow phenomena in thermal processes…”

“…The microwave processing has been studied for the drying and firing (sintering) of some ceramics; microwave applied for sintering of ceramics was identified to be a very interesting alternative achieving finer microstructure, improved mechanical properties, with lower processing times and energy consumption [106].…”

“…Eight times reduction in firing time leading to fuel savings [51]; 7-30 times reduction in drying time leading to fuel savings [95]. [51,95,106] Kiln cars and furniture with low thermal mass Use of low thermal mass (LTM) kiln cars to decrease the thermal energy requirement for the heating of supporting refractories; they offer similar strength and stability comparative to traditional construction materials with the advantage of having lower running costs, repairs, downtime and maintenance [52,53]; LTM materials include Si 3 N 4 and SiC [111].…”

Microwave Annealing of Powder Metals without Sintering

“…Microwave (MW) heating of materials is used for the synthesis, sintering, curing and heat treatment of ceramic, metal, polymer and composite materials. The main advantages of microwave processing are rapid heating, selectivity of heating and shortening of process times [9,10]. Susceptor assisted microwave annealing was proposed for fabrication of silicon based semiconductors in US20120196453A1 [11].…”

Synthesis and Characterization of Hollow Glass Sphere Containing Aluminum Syntactic Foam by Spark Plasma Sintering and Hot Pressing

“…The density and mechanical properties of composites are found to be generally higher in HP than in PLS [13]. On the other hand, spark plasma sintering (SPS) process has lower sintering temperature, short sintering time and higher heating rates than PLS or HP [14,15]. By the high energy plasma that is generated during the process between unconsolidated powders, the dense oxide film on the surface of Aluminum (Al) powder can be easily broken during the SPS process.…”