Field Assisted Sintering (FAST), also known as Spark Plasma Sintering (SPS), is an innovative sintering technique that has been receiving considerable attention in the last few years. FAST offers the possibility of obtaining fast sintering at lower temperatures. Due to these characteristics, it found wide application in the case of hard to sinter materials, such as high-temperature ceramics or nanopowders.
In the case of nanopowders, the lower temperatures and shorter times allowed obtaining near theoretical density values with little grain growth. As a result, FAST/SPS has rapidly become the technique of choice for the realization of bulk nanostructured materials.
Despite the wide application, the microscopic mechanisms responsible for its characteristics are still debated. Large emphasis has been given to the role that the electric field or the high current involved in the technique might play on sintering. However, a robust experimental validation is still lacking.
Our group has been pioneering the investigation on the microscopic mechanisms involved in the technique and on the application of the FAST/SPS to the realization of bulk nanostructured materials presenting innovative properties, particularly in the field of ceramic ionic conductors. We collaborated with the introduction of a high-pressure modification of the technique known as High-Pressure Field Assisted Sintering (HP-FAST), which resulted in being particularly useful in this respect. The possibility to extend the range of the applied uniaxial pressures up to 4 GPa allows a further reduction of grain growth.
To obtain full control of the experimental parameters involved in the process, we have been developing our machines, and we are continually developing new approaches to extend the application of the techniques towards new materials.
Related publications:
I.G. Tredici, F. Maglia, C. Ferrara, P. Mustarelli, and U. Anselmi-Tamburini, “Mechanism of Low-Temperature Protonic Conductivity in Bulk, High-Density, Nanometric Titanium Oxide,” Advanced Functional Materials, 24 [32] 5137–5146 (2014).
D. Cadavid, M. Ibáñez, U. Anselmi-Tamburini, O.J. Durá, M.A. López de la Torre, and A. Cabot, “Thermoelectric properties of bottom-up assembled Bi2S3–xTex nanocomposites,” Int. J. Nanotechnol, 11 [9/10/11] 773–784 (2014).
M.T. Buscaglia, F. Maglia, U. Anselmi-Tamburini, D. Marré, I. Pallecchi, A. Ianculescu, G. Canu, M. Viviani, et al., “Effect of nanostructure on the thermal conductivity of La-doped SrTiO3 ceramics,” Journal of the European Ceramic Society, 34 [2] 307–316 (2014).
S. Muñoz and U. Anselmi-Tamburini, “Parametric investigation of temperature distribution in field activated sintering apparatus,” The International Journal of Advanced Manufacturing Technology, 65 127–140 (2013).
F. MAGLIA, I.G. Tredici, and Anselmi-Tamburini, “Densification and properties of bulk nanocrystalline functional ceramics with grain size below 50 nm,” JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 33 1045–1066 (2013).
T.B. Holland, U. Anselmi-Tamburini, and A.K. Mukherjee, “Electric fields and the future of scalability in spark plasma sintering,” Scripta Materialia, 69 [2] 117–121 (2013).
U. Anselmi Tamburini, G. Spinolo, F. Maglia, I. Tredici, T.B. Holland, and A.K. Mukherjee, “Field Assisted Sintering Mechanisms”; pp. 159–191 in Sintering Mechanisms of Convention Nanodensification and Field Assisted Processes, Ricardo Castro and Klaus van Benthem. Springer, 2013.
I.G. Tredici, F. Maglia, M. Dapiaggi, G. Spinolo, and U. Anselmi-Tamburini, “Synthesis of bulk tetragonal zirconia without stabilizer: The role of precursor nanopowders.,” J. Eur. Ceram. Soc., 32 [2] 343–352 (2012).
F. Maglia, M. Dapiaggi, I.G. Tredici, and U. Anselmi-Tamburini, “Synthesis of fully dense anatase TiO2 through high pressure field assisted rapid sintering.,” Nanosci. Nanotechnol. Lett., 4 [2] 205–208 (2012).
F. Maglia, F. Farina, M. Dapiaggi, I.G. Tredici, and U. Anselmi-Tamburini, “Transport properties in bulk nanocrystalline Sm-doped ceria with doping content between 2 and 30at.%,” Solid State Ionics, 225 412–415 (2012).
T.B. Holland, T.B. Tran, D.V. Quach, U. Anselmi-Tamburini, J.R. Groza, and A.K. Mukherjee, “Athermal and thermal mechanisms of sintering at high heating rates in the presence and absence of an externally applied field.,” J. Eur. Ceram. Soc., 32 [14] 3675–3683 (2012).
T.B. Holland, U. Anselmi-Tamburini, D.V. Quach, T.B. Tran, and A.K. Mukherjee, “Local field strengths during early stage field assisted sintering (FAST) of dielectric materials.,” J. Eur. Ceram. Soc., 32 [14] 3659–3666 (2012).
T.B. Holland, U. Anselmi-Tamburini, D.V. Quach, T.B. Tran, and A.K. Mukherjee, “Effects of local Joule heating during the field assisted sintering of ionic ceramics.,” J. Eur. Ceram. Soc., 32 [14] 3667–3674 (2012).
U. Anselmi-Tamburini, F. Maglia, and I. Tredici, “Field assisted sintering of nanometric ceramic materials”; pp. 133–150 in Advances in Sintering Science and Technology II, Edited by Suk-Joong L. Kang, Rajendra Bordia, Eugene Olevsky and Didier Bouvard. American Ceramics Society, 2012.
D.V. Quach, J.R. Groza, A. Zavaliangos, and U. Anselmi-Tamburini, “Fundamentals and applications of field/current assisted sintering.”; pp. 249–274 in Sintering of Advanced Materials. Edited by Z.Z. Fang. Woodhead Publishing Ltd., 2010.
U. Anselmi-Tamburini, Z.A. Munir, and J.E. Garay, Preparation of dense nanostructured oxide ceramics with fine crystal size by high-pressure spark plasma sintering.; US Patent 20090224434A1, 2009.