Spark Plasma Sintering Research
(2011) Cryomilling and Spark Plasma Sintering of 2024 Aluminium Alloy. PhD thesis, University of Trento.
Synthesis and spark plasma sintering of nano …
Heterogeneous photo-catalysis is an advanced oxidation process (PAO), which has been the subject of numerous studies and applications, particularly using the commercial oxide of TiO2 (P25, Evonik). Zinc oxide (ZnO) has often been considered a valid alternative to TiO2 due to its good opto-electronic, catalytic and photochemical characteristics along with its low cost. In order to improve the photocatalytic performance of ZnO for practical applications, various types of synthetic approaches have been developed, including, among others, the hydrothermal / solvothermal growth method, sol-gel method, ultrasonic assisted method, deposition chemistry in vapor phase, etc. with the aim of preparing ZnO particles with different sizes and morphologies. However, all of these methods require relatively severe reaction conditions such as high temperature, sophisticated techniques, high purity of gases, adjustable gas flow, expensive raw materials, etc. Therefore, it is important to find a simple and cost-effective method for the synthesis of crystalline nano-particles of ZnO. For this reason, in the present work, the ZnO has been synthesized by three different procedures: conventional aqueous precipitation method, hydrothermal method (H) and microwave assisted method (MW). In all three processes, the same material is obtained, hydrocincite [Zn5(CO3) 2(OH)6], which evolves to crystalline ZnO after calcination thermal treatments. We investigated the effect of the calcination temperature, at the same time (2 h), on the optical, textural and structural properties. Photo-catalytic studies were performed using two selected substrates, Methyl Orange and Phenol, as toxic model substrates (one colorant and the other transparent). The catalysts prepared were characterized by several techniques: DRX, SBET, FE-SEM, TEM and UV-Vis (in diffuse reflectance mode).From the results of XRD, it has been possible to establish that a minimum difference between the relative intensities of exposed faces (I100 and I002) is a crucial factor to obtain good photocatalytic properties. This minimum difference is achieved, in our cases by thermal treatments of calcination at 400ºC, 2 h. When this temperature is chosen, there is no appreciable variation between the photocatalytic activities of the oxides of zinc obtained by the three processes, and there are small differences depending on the nature of the substrate chosen, which can be attributed to the textural differences between the oxides. In any case, the obtained zinc oxides show, for each substrate, photo-catalytic activities in the UV that are superior to those presented by the widely used commercial oxide TiO2 (P25) used as reference.
Aluminium diffusedfrom the matrix into the fibres, resulting in the formation of Al4C3 in the carbon fibre and TiC in the matrix surrounding the fibre.AFRIKAANSE OPSOMMING: 'n Koolstof-versterkte MAX-fase keramieksamestelling was in 'prepreg' vorm geleweren gesinter deur gebruik te maak van vonk plamsa-sintering (VPS).
Spark plasma Sintering | Sintering | Materials
Spark plasma sintering is a method of consolidating nanostructured powder materials and also composites and gradient materials in the presence of an electromagnetic field, by means of low-voltage sources of powerful current. The main benefit of spark plasma sintering is that previously impossible structures, properties, and compositions may be produced. The finite-element method is used to analyze the consolidation of samples by spark plasma sintering and by a hybrid method in which spark plasma sintering is combined with hot pressing. Corresponding numerical models are tested.
Numerical modeling of the spark plasma sintering of square plates from aluminum-oxide and tungsten-carbide powder is considered. The rounding radius of the plates is 0.8, 1.2, or 1.6 mm. The distribution of the temperature and mechanical stress within each sample and also within the mold is determined. The results are used for preliminary assessment of the possibility of spark plasma sintering of cutting plates.
Spark plasma sintering and porosity studies of uranium …
The electrical and thermal properties of the doped Tellurium Telluride (Tl10Te6) chalcogenide nano-particlesare mainly characterized by a competition between metallic (hole doped concentration) and semi-conducting state. We have studied the effects of Sndoping on the electrical and thermoelectric properties of Tl10-xSnxTe6 (1.00 ≤x≤ 2.00), nano-particles, prepared by solid state reactions in sealed silica tubes and ball milling method. Structurally, all these compounds were found to be phase pure as confirmed by the x-rays diffractometery (XRD) and energy dispersive X-ray spectroscopy (EDS) analysis. Additionally crystal structure data were used to model the data and support the findings. The particles size was calculated from the XRD data by Scherrer’s formula. The EDS was used for an elemental analysis of the sample and declares the percentage of elements present in the system. The thermo-power or Seebeck co-efficient (S) was measured for all these compounds which show that S increases with increasing temperature from 295to 550 K. The Seebeck coefficient is positive for the whole temperature range, showing p-type semiconductor characteristics. The electrical conductivity was investigated by four probe resistivity techniquesrevealed that the electrical conductivity decreases with increasing temperature, and also simultaneously with increasing Snconcentration. While for Seebeck coefficient the trend is opposite which is increases with increasing temperature. These increasing behavior of Seebeck coefficient leads to high power factor which are increases with increasing temperature and Sn concentration except For Tl8Sn2Te6 because of lowest electrical conductivity but its power factor increases well with increasing temperature.
Phase-pure and ion-substituted calcium phosphates andzirconia-hydroxyapatite phase mixtures were spark plasma sintered to high densitieswith these materials displaying good mechanical properties.
Spark plasma sintering of cutting plates | SpringerLink
Spark plasma sintering and hardness.
spark plasma sintering ..
Spark plasma sintering and porosity studies of uranium nitride
Synthesis and spark plasma sintering of nano-structured ceramic materials for armour application
Spark Plasma Sintering (SPS) ..
Spark plasma Sintering - Free download as PDF File (.pdf), Text File (.txt) or read online for free.
Spark plasma sintering of aluminum nitride.
There have been many investigations on metal matrix microcomposites produced by conventional casting routes; however, in the past decade, the focus has shifted more toward nanocomposites produced via solid state routes. To have a realistic view of performance prediction and optimum design of such composites, in this work Al matrix composites (AMCs) reinforced with WC microparticles, nanoparticles, and bimodal micro-/nano-particles were prepared by spark plasma sintering. The effects of particle size and concentration, and process variables (i.e. sintering temperature, duration, and pressure) on the evolution of microstructure, density and hardness of the composites were studied comprehensively. Full densification of AMCs with high particle concentration was problematic because of ceramic cluster formations in the microstructure. This effect was more emphasized in AMCs containing nanoparticles. AMCs with microparticles were more easily densified, but their hardness benefits were inferior. On the other hand, the mixture of micro- and nano-particles in Al-WC bimodal composites led to better matrix reinforcement integrity and an overall improvement in the microstructural properties. Finally, increasing the sintering temperature improved the microstructural features and hardness of the composites (more enhanced in high wt.% samples), but sintering duration and pressure did not have a big impact on the composite properties.
Spark plasma sintering is a powerful method to produce fine ..
Thanks to its high heating rate combined with a moderate pressure, spark plasma sintering (SPS) is capable of producing a fine-grain spinel without using a sintering aid.
Spark Plasma Sintering Apparatus Used for the …
In order to minimize the interfacial reaction betweenthe reinforcements and the Fe-50Co alloy (matrix) and to realise higher compact density,spark plasma sintering (SPS) was selected for rapid compaction of materials.
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