The sps process is based on the electrical spark discharge phenomenon. The tungsten based nuclear cermets fabricated by sps will not only be applicable for the space exploration application but also for the ground based nuclear reactors. It addresses fundamentals and materialspecific considerations, techniques, and applications across a broad spectrum of materials. Spark plasma sintering sps, a sintering method that uses the action of pulsed direct current and pressure, has received a lot of attention due to its capability of exerting control over the microstructure of the sintered material and flexibility in terms of the heating rate and heating mode. Spark plasma sintering sps is a process which allows powder densification, applying simultaneously a uniaxial external load and pulsed direct current of very high intensity through tools. This process describes a new approach for the synthesis of hydroxyapatite. Us6384365b1 us09549,462 us54946200a us6384365b1 us 6384365 b1 us6384365 b1 us 6384365b1 us 54946200 a us54946200 a us 54946200a us 6384365 b1 us6384365 b1 us 6384365b1 authority us united states prior art keywords opposing surfaces method approximate turbine component turbine prior art date 20000414 legal status the legal status is an assumption and is. The idea of flash spark plasma sintering or flash hot pressing fhp stems from the conducted theoretical analysis of the. Spark plasma sintering of fuel cermets for nuclear reactor applications yang zhong1, 2, robert c. A spark plasma sintering sps process has been explored to densify fjs.
One of the main goals of the sps modeling is to be able to predict the densification of the powder during the process. Spark plasma sintering sps is a short time consolidation technique, which enables rapid sintering and synthesis of various materials metals, ceramics and composites applying dc current pulses with several hundred or thousand ampere while mechanical pressure is applied. Jerred, kristopher schwinn, laura sudderth 1 and joshua hundley 1center for space nuclear research, idaho national laboratory, id 83415, u. It was originally claimed by inoue and the sps process inventors that the pulses generated sparks and even plasma discharges between the particle contacts, which were the reason that the processes were named, spark plasma sintering and plasma activated sintering inoue, 1965, yanagisawa et al. Its processing parameters are usually lowvoltage and lowpressure acting, using a uniaxial force and pulsed direct current dc to carry out high efficiency consolidation of the powder. Spark plasma sintering sps initial activation of powders by pulsed voltage.
This technique has been widely applied for various materials processing in the recent years. A new ultrarapid process of flash spark plasma sintering is developed. Microstructures of binderless tungsten carbides sintered by spark plasma sintering process. The model 104 spark plasma sintering sps system from thermal technology llc introduces a revolutionary highspeed powder consolidation process. Multiscale microstructures of stacking fault, dislocation, and oxygen vacancylinked defects could be. It addresses fundamentals and materialspecific considerations, techniques, and applications across a broad spectrum of materials, and emphasizes optimization of speed, mechanical and wear properties, and energy efficiency. Sintering technology or spark plasma sintering in the heat treatment group at fraunhofer institute for ceramic technologies and systems ikts. This paper focuses on the cermets for ground based nuclear reactor applications. Spark plasma sintering sps is a highspeed powder consolidation sintering technology capable of processing conductive and nonconductive materials. Microstructure evolution during spark plasma sintering of fjs. The process by which spark plasma sintering produces high densification of powder specimens is examined to determine the role of sparks and plasma. Fabrication of porous materials by spark plasma sintering.
Sintering and reactive sintering by spark plasma sintering. The key step in powder metallurgy process beside others, is sintering. This newly developed technique is regarded as an energysaving technology due to its short process time and few processing steps. Improved understanding of the spark plasma sintering process. Spark plasma sintering sps is a newly developed process a synthesis and processing technique which makes it possible for sintering and sinterbonding at low temperatures and short periods by charging the intervals between powder particles with electrical energy and effectively applying a high temperature spark plasma which is generated momentarily. Sem micrographs of the samples sintered at 1150c for 3 min, with pressure applied. Spark plasma sintering sps, also called the pressureassisted pulse energizing process or the pulsed electric current sintering pecs process, is a promising technology for innovative processing in the field of new materials fabrication in the 21st century. However, the determination of the optimal sintering condition. Some fundamentals on spark plasma sintering as a processing. This process allows the sintering of materials in few minutes compare to hours by conventional sintering.
Among these fabrication techniques for synthesizing the composites, spark plasma sintering sps has attracted much attention, because of its low energy consumption and very short sintering time. This technique is expected to be a new process for sintering various kinds of materials 4752. Fundamentals of sintering as a process to consolidate powders spark plasma sintering. We discovered that a small amount of dopants can lower the starting temperature of densification during spark plasma sintering sps. This newly developed technique is regarded as an energysaving technology due to its short process time and few processing. Fast techniques are considered to be better than conventional sintering methods such as hp or hip, as they can produce materials with superior properties 5860.
May 01, 2008 the spark plasma sintering process offers significant improvements over conventional hot press and hot isostatic press sintering. The sintering of nanosize powders of fully stabilized zirconia was investigated using the spark plasma sintering sps method. The advantages of spark plasma sintering such as high heating rates, short sintering cycles, and low sintering temperatures that allow sintering nanostructured materials were emphasized by all researchers. The pulsed dc power supply is connected to the upper and lower punches. Nercf spark plasma sintering system college of engineering. This leads to individual powder particles adhering to each other in a dense compact. Allmaterialsinclusive flash spark plasma sintering. Spark plasma sintering sintering is the process of making objects from powder, by heating the material in a furnace below its melting point so that bonding takes place by diffusion of atoms. A new sintering technique known as spark plasma sintering sps appears as the only method to reach high densities while preserving the final grain size within the nanometric range, with the added advantage of carrying out the process at significantly lower temperatures and shorter times as compared with the classical processes.
Effect of spark plasma sintering sps on the thermoelectric properties of magnesium ferrite, materials for renewable and sustainable energy, 2016, pp. Sep 14, 2016 a new ultrarapid process of flash spark plasma sintering is developed. A model has been developed to simulate the heat transfer behavior during spark plasma sintering sps process and by using the pure spherical copper particles as an example, the temperature. The spark plasma sintering process offers significant improvements over conventional hot press and hot isostatic press sintering. Spark plasma sintering of fuel cermets for nuclear reactor. Spark plasma sintering sps technique is one of the hightechnology sintering process that has been used to prepare the large number of composite materials4,5.
Since only surface layers of the powder particles are heated in the spark plasma sintering process, the average monitored temperature of the compact is relatively low. The aim of the study was to investigate the role of microstructure and porosity on the mechanical behaviour of sintered hydroxyapatite synthesized by polyol process. Enhanced mechanical properties of light alloys based on solidstate reactions during a combination of mechanical milling and spark plasma sintering process 7. This direct way of heating allows the application of very high heating and cooling rates. Application of the spark plasma sintering technique to low. Spark plasma sintering seminar sintering plasma physics. Spark plasma sintering of materials advances in processing. Spark plasma sintering sps or pulsed electric current sintering pecs is a sintering techni. Oct 31, 2017 while the term spark plasma sintering is commonly used, the term is misleading since neither a spark nor a plasma is present in the process.
Spark plasma sintering sps is a novel technique that uses pressuredriven powder consolidation in which a pulsed direct electric current passes through a sample compressed in a graphite matrix. Numerical modeling of the spark plasma sintering process. Pdf microstructures of binderless tungsten carbides. Spark plasma sintering problem statement spark plasma sintering sps, also known as pulsed electric current sintering pecs or field assisted sintering technology fast, employs a pulsed dc current to heat up an electrically conductive tool and possibly powder compact by joule heating. Viscous and diffusion mechanisms of mass transport 3. Spark plasma sintering sps is a sintering technique utilizing uniaxial force and a pulsed direct current to perform metallic or ceramic particle consolidation in very short times. The spark plasma sintering is a breakthrough way of elaboration of more or less complex shape materials from powder.
Measurements are reported of the electromagnetic emission during the pulsing current using the stateoftheart tektronix mdo4104b6 to obtain voltage vs time and simultaneously radio frequency rf emission in selected power vs frequency regions. Challenges and opportunities for spark plasma sintering. Low temperature sintering of aluminumzircon metal matrix. Spark plasma sintering advanced ceramics and powder metallurgy. The book highlights methods used to consolidate metallic or ceramic particles in very short times. Spark plasma sintering advanced ceramics and powder. Spark plasma sintering an overview sciencedirect topics. Gaffet and others published spark plasma sintering find, read and cite all the research you need on researchgate.
Microstructure evolution during spark plasma sintering of. Sintering is a thermally activated transition of a powder or porous system to thermodynamically more equilibrium states through a decrease of the free surface energy one of the emerging technology in rapid prototyping is spark plasma sintering its application is quite promising in aerospace industries. Recently, the spark plasma sintering method sps launched commercially and significantly paid attention in pm. Rapid prototyping is a technology which has such potential.
Besides technological aspects of fastsps, scalability, tool design, process optimization fem, temperature measurement. Applications of spark plasma sintering takashi goto fl hhk imr, tohoku university institute for materials researc h, tohoku university, japan 2nd international schoolseminar perspective technology of materials consolidation with electromagnetic fields 1st russiajapan sps workshop moscow, russia, may 2022, 20 outline introduction. The sps process is a solid consolidation sintering process with simultaneous. As reported6, sps introduces two important factors in a process of sintering. The spark plasma sintering process has been shown to be an effective technique for consolidating metallic materials including nanocomposites. Powder densification modeling of the sparkplasmasintering. We conducted studies on yb 22 c 2 n spark plasma sintered with additions of yb 4 and yb 25 c, including the investigations of the densification process and the thermoelectric properties of the material. Spark plasma sintering sps is performed in a graphite.
Misfitlayered ca3co4o9 as a ptype semiconductor is difficult to commercialize because of its relatively poor performance. Figure 18 37 can be used to compare the microstructure of an intermetallic alloy. The sps technique enables an increased sintering kinetics of a broad group of materials. Spark plasma sintering sps, also known as pulsed electric current sintering pecs or field assisted sintering technology fast, employs a pulsed dc current to heat up an electrically conductive tool and possibly powder compact by joule heating. Today, spark plasma sintering is emerging as a possible method to obtain advanced materials instead of the hip process. Sintering is the process of making objects from powder, by heating the material in a furnace below its melting point so that bonding takes place by diffusion of atoms.
Thermoelectric properties and spark plasma sintering of. A strategy to optimize the thermoelectric performance in a. Ceramicmetal nanocomposites by lyophilization and spark plasma sintering method in a vickers diamond microindenter leco 100a microindentation hardness testing system, usa on surfaces of cross sections polished down to 1 micron, with an applied load of 0. Apr 19, 2017 spark plasma sintering sps is one of the state of the art techniques for the facile consolidation of virtually all ceramic and metallic powders 1,2,3,4,5. Spark plasma sintering sps is a relatively new process for ceramication which has a shorter processing time and lower sintering temperature compared with other processes such as hip. Spark plasma sintering sps is a versatile technique used to rapidly fabricate a number of materials including metals 18, ceramics 19,20 and. Application of spark plasma sintering for manufacturing of. Us6384365b1 repair and fabrication of combustion turbine. This book describes spark plasma sintering sps in depth. Sep 20, 2019 a spark plasma sintering sps process has been explored to densify fjs.
Extrapolation of sintering concepts towards constitutive modeling of sps 6. Flash ultrarapid sparkplasma sintering of silicon carbide. The influence of sintering temperature, heating rate, direct current pulse pattern, sintering time, and sintering pressure on the final density and grain size of. On the role of the electrical field in spark plasma sintering. Sps utilizes highamperage pulsed dc current to activate the consolidation and reaction sintering of materials. Joule heating has been found to play a dominant role in. Effect of spark plasma sintering sps on the thermoelectric.
Equiatomic feco alloys with average particle size of 24. Refined sps modelling based on calibrated current and voltages measurements 8. Department of mechanical engineering snm institute of management and technology, maliankara ernakulam introduction in globalization era, customers are looking for products having 1 high accuracy 2 customized and complex design. The influence of sintering temperature, heating rate, direct current pulse pattern, sintering time, and sintering pressure on the final density and grain size of the product was investigated.
Pdf effect of spark plasma sintering process on the. The idea of flash spark plasma sintering or flash hot pressing fhp stems from the. The load commonly up to 15000 psi100 mpa is transferred to the powder through the upper punch. Tial, used for aeronautical applications made by two different routes hot isostatic pressing and spark plasma sintering in an attempt to obtain similar microstructures. The effect of sps conditions, such as temperature and p. Optimization of process parameters for spark plasma. The spark plasma sintering sps process is an ecas technique that combines the benefits of highly pulsed electric current 8000 a, high pressure up to 100 mpa, high temperatures up to. Influence of spark plasma sintering parameters on magnetic. Boosting the thermoelectric performance of calcium.
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