Project

Discipline

Spark Plasma Sintering; Densification; Nanocomposite; Thermoelectrics; Nanostructure

Lead
Lay summary
Spark plasma sintering (SPS) is a revolutionary high-speed powder consolidation technology of broad application potential. During SPS, the precursor powders are typically loaded in a graphite die and fast heating is achieved by passing a pulsed DC electrical current through the die and the sample while uniaxial pressure is applied on the powder. The characteristics of SPS processing include high heating rates, the application of pressure during the sintering and the tunability of the microstructure via variable pulsed electrical currents. The essential advantages of SPS-based technologies over conventional sintering methods are lower sintering temperatures, shorter exposure to elevated temperatures, no need for binder or additives as well as important improvements in the mechanical and physical properties of the sintered materials. Successful installation of SPS in the Laboratory for Solid State Chemistry and Catalysis, Empa will provide the open opportunity to harvest the necessary knowledge to start-up new science and technology for the development of innovative materials. The main purpose of using SPS is to produce a wide range of innovative materials that so far had not been possible to synthesize and/or to consolidate by conventional sintering methods. For example, SPS will be used for the sintering of ceramic materials such as oxynitride perovskites for photoelectrochemical water splitting, nanostructured ruthenates for electronic applications, intermetallics for thermoelectric converters, titanates for memristor materials, carbon nanotube composite materials for battery applications. SPS also has huge potential for industrial application as it is a scalable, energy-saving sintering method allowing rapid manufacturing of monophasic nano-scaled materials and composites. Therefore, SPS will be not only used as versatile equipment for fundamental R&D purposes but also for industrial-scale production of nano­structured materials. As no SPS apparatus has been installed in Switzerland up to now, cooperation with different partners will benefit academies, national institutes and industry involved with material science & engineering and solid state chemistry & physics. On the one hand, SPS allows the production of innovative materials which could not be synthesized with conventional methods and, on the other hand, will be crucial for materials testing and research with the objective of developing more cost-efficient production methods for improved sintered materials.

Direct link to Lay Summary

Last update: 21.02.2013

Number	Title	Start	Funding scheme

The ever increasing demand for advanced multifunctional materials with defined and engineered micro/nano structures has stimulated the search for innovative methods to densify nano-scaled materials. Currently emerging densification techniques which simultaneously preserve an ultrafine microstructure are based on new sintering concepts exploiting the effect of pulsed currents, high-frequency electromagnetic fields, high strain rates combined with severe deformation, and mass-transport enhancing electron-beam irradiation. Several of these unconventional sintering procedures have already been shown to markedly improve the mechanical, chemical or physical properties and considerably reduce processing time, energy consumption and ecologically harmful effects.Spark Plasma Sintering (SPS) is a revolutionary high-speed powder consolidation technology of broad application potential. During SPS, the precursor powders are typically loaded in a graphite die and fast heating is achieved by passing a pulsed DC electrical current through the die and the sample while uniaxial pressure is applied on the powder. The characteristics of SPS processing include high heating rates, the application of pressure and the effects of electrical currents and fields. The essential advantages of SPS-based technologies over conventional sintering methods, like pressure¬less sintering, gas-pressure sintering, hot-pressing or hot isostatic pressure (HIP) are lower sintering temperatures, shorter exposure to elevated temperatures, no need for binder or additives as well as important improvements in the mechanical and physical properties of the sintered materials.SPS has also demonstrated its potential as an energy-saving sintering method in nanotechnology allowing rapid manufacturing of monophasic materials and composites, and of materials for biomedical as well as energy-harvesting applications. This technique will also be of interest to the materials manufacturing, energy, information technologies, health care (biomaterials), automotive and aeronautic industry. SPS is not only suited as a versatile equipment for fundamental R&D purposes but also for industrial-scale production of nano-structured materials.To the best of our knowledge, no SPS equipment has been installed in Switzerland up to now. SPS will be essential for academies, national institutes and industry involved with material science & engineering and solid state chemistry & physics such as the Laboratory for High Performance Ceramics at Empa Duebendorf and the Laboratory for Advanced Materials Processing at Empa Thun. Moreover, SPS will be useful for the Department of Chemistry and Biochemistry at the University of Bern, the CSEM, Centre Suisse d' Electronique et de Microtechnique (Swiss Center for Electronics and Microtechnology) and the Department of Materials at ETH Zurich for joint research activities. Finally, international collaboration with South Korea and Japan is also highly anticipated in order to encourage knowledge exchange and inter-institute research activities. On the one hand, SPS allows the production of innovative materials which could not be synthesized with conventional methods and, on the other hand, will be crucial for materials testing and research with the objective of developing more cost-efficient production methods for improved sintered materials.