Dense spark plasma sintering

Takeuchi, T., Tabuchi, M., Kondoh, I., Tamari, N., Kageyama, H., (2000), Synthesis of dense lead titanate ceramics with submicrometer grains by spark plasma sintering , J. Am. Ceram. Soc., 83, 541-544. 

Alternative processing methods also offer the potential to control the microstructure and final properties of nanocomposites. Both self-propagating high-temperature sintering and spark plasma sintering offer means to obtain metastable yet dense nanocomposites. Subsequent heat treatments can then be used to approach equilibrium microstructures, where the properties will be a function of the heat treatment temperature and time. In this way a variety of microstructures, and thus variations of the composite properties, can become available. 

From the above results, it is confirmed that the Co composition graded cemented carbide/steel composite sinter- bonded by spark plasma sintering is sintered densely and also relieved of thermal stress. Therefore this composite material is expected to display the excellent properties as desired. 

By using spark plasma sintering, the Co composition graded green compact of cemented carbide sinter-bonded on steel substrate could be sintered densely and the desired graded structure was maintained after sintering. 

Fabrication of dense p-SiAlON by a combination of combustion synthesis (CS) and spark plasma sintering (SPS). IntermetalUcs, 18, 536—541. 

Pure and dense P-Sis. Al O Ng. s were synthesized by SHS (CS) followed by spark plasma sintering without any sintering additives (Chapter 4). The hardness, thermal conductivity, and the corrosion resistance in different atmospheres were investigated for the application as high temperature engineering materials. 

Balazsi et al. [72] carried out extensive experimental work to analyse the effectiveness of the SPS method compared to conventional hot isostatic pressing for silicon nitride composites with 6 wt.% MWCNTs. For spark plasma sintered samples, different sintering conditions such as temperature and holding time were investigated to find the most suitable processing parameters. It was shown that dense samples with improved mechanical properties were achieved at comparatively lower sintering temperatures by SPS [72]. At least a 100% increase in the modulus of elasticity (around 300GPa) was achieved for spark plasma sintered samples compared to hot isostatic pressed samples. 

Spark plasma sintering (SPS) is one of the solid consolidation processes which is carried out in a graphite mold and the heating is accomplished by spark discharges in voids between particles [10]. Whether a plasma is generated has not yet been confirmed, especially when non-conducting ceramic powders are compacted. However it has been experimentally verified that the densification is enhanced by the use of DC pulses [11]. Various materials have been compacted by SPS technique. Zhao et al. fabricated dense 50 nm BaTiOs ceramics (97% relative density) by SPS [12]. Very recently, Buscaglia et al. demonstrate that the 30 nm BaTiOs ceramics system is still... 

J.K. Park, U.J. Chung, D.Y. Kim, Application of spark plasma sintering for growing dense Pb(Mgl/3Nb )03-35 mol% PbTi03 single crystal by solid-state crystal growth, J. Electroceram. 17 (2006) 509-513. 

V. Tyrpekl, M. Holzhauser, H. Hein, J J. Vigier, J. Somers, P. Svora, Synthesis of dense yttrium-stabilised hafnia pellets for nuclear appUcations by spark plasma sintering, J. Nucl. Mat. 454 (2014) 398-404. 

Figure 331 A combination of the sol-gel process and spark plasma sintering that yields nanostructured dense monoliths. The thermal conductivity can be fine-tuned through the...

The previous researeh results indieated that spark plasma sintering is very effective to fabrieate MAX phases, espeeially Ti3SiC2. Thanks to SPS, the high purity and highly dense Ti SiC phase eould be fabrieated in one step, even the MAX-based... 

Reaction between elemental boron and metal powder is the simplest route to produce boride powder. It can have excellent control on the stoichiometry of the resultant boride. Although this route results in pure ZrB /HfB but cannot be employed for industrial production because the starting materials used are expensive. This route can be exploited to get dense shapes of borides by hot pressing or spark plasma sintering of mixed powder (metal and boron), if the reaction with die is avoided (Tamburini et al., 2008). To avoid any reaction with the die, the graphite die is coated with boron nitride. 

Spark plasma sintering (SPS) is a novel technique, which gives dense shapes of UHTCs at a lower temperature and in a shorter time compared with conventional techniques. In the SPS technique, a pulsed direct current passes through graphite plungers and dies simultaneously with a uniaxial pressure. Figure 3 presents the schematic of spark plasma sintering. 

Development of new densification techniques which can give dense bodies of various shapes. New techniques such as spark plasma sintering and microwave sintering are being used for UHTCs. Advancements are needed to make these techniques capable to produce complex shapes. Moreover new techniques with better features need to be invented. 

Tamburini, U., Kodera, Y., Gasch, M., Unuvar, C., Munir, Z. A., Ohyanagi, M. (2006). Synthesis and characterization of dense ultra-high temperature thermal protection materials produced by field activation through spark plasma sintering (SPS), hafnium diboride. Journal of Materials Science, 41,3097-3104. doi 10.1007/ sl0853-005-2457-y. 

An overview on the state of the art concerning fabrication of dense UHTC with improved performances is presented. The most important sintering methods such as, hot pressing, spark plasma sintering and reactive hot-pressing, pressureless sintering etc. are briefly summarized. 

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