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Journal articles on the topic 'Hard-phase synthesis'

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Published: 30 May 2022
Last updated: 31 May 2022

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1

Saito, Tetsuji, and Masaki Ichihara. "Synthesis and magnetic properties of Sm5Fe17 hard magnetic phase." Scripta Materialia 57, no. 6 (September 2007): 457–60. http://dx.doi.org/10.1016/j.scriptamat.2007.05.037.

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2

Chen, Z. S., W. P. Yang, and C. W. Macosko. "Polyurea Synthesis and Properties as a Function of Hard-Segment Content." Rubber Chemistry and Technology 61, no. 1 (March 1, 1988): 86–99. http://dx.doi.org/10.5254/1.3536179.

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Abstract High-molecular-weight linear polyureas of different hard-segment content are obtained with a two-step solution polymerization. Elimination of water, careful choice of solvent, reactant concentration, and good control of reaction temperature are essential to obtain satisfactory results. We have studied the influence of the hard-segment content on the mechanical, dynamic-mechanical, and thermal properties of these solution polymerized amine-terminated polypropylene-oxide-based thermoplastic polyureas. Two-phase morphology is predominant within the range of the hard-segment concentration studied. Inversion of the continuous and dispersed phase might occur in the polyurea series at about 60 wt.% of hard segment. This changes the nature of the polyureas from a tough elastomeric material to a more brittle, high-modulus plastic. The modulus of the rubbery plateau measured from dynamic-mechanical spectra increases with hard-segment concentration due to the reinforcing effect of hard-segment domains. However, continuous improvement in dynamic-mechanical modulus is not significant when the hard segment is above 50 wt.% due to higher degree of phase mixing in high hard-segment concentration systems. The amount of solubilized hard segment in the soft-segment phase in these polyureas is limited as judged from the relatively constant soft-segment Tg. However, the extent of phase separation, as determined by the heat capacity change ΔCp across the soft-segment Tg, decreases with increasing hard-segment content. The same characterizations and analyses have also been carried out on a series of RIM produced polyurea samples of the same composition. Great difference in properties is observed in comparison of these two sets of samples due to their different synthesis routes. In general, samples produced by RIM exhibit lower molecular weight, lower dynamic-mechanical modulus, higher soft-segment Tg, more phase-mixed, and more tensile elongation than those synthesized by solution polymerization. The detailed comparison will be treated in a separate paper.
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3

Tsonev, Tsvetomir, Michael Herzog, and Sanchi Nenkova. "Shape memory polyurethanes based on recycled polyvinyl butyral. I. Synthesis and morphology." Open Chemistry 11, no. 12 (December 1, 2013): 2058–65. http://dx.doi.org/10.2478/s11532-013-0331-3.

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AbstractShape memory polyurethanes (SMPUs) were synthesized by 4,4′-diphenylmethane diisocyanate (MDI), hexane-1,6-diol (HD), polypropylene glycol (PPG), and recycled polyvinyl butyral (PVB). Dynamic mechanical analysis, differential scanning calorimetry and Fourier transformation infrared attenuated total reflection spectroscopy was used to characterize the poly (vinylbutyral-urethanes). Micro-phase domain separation of hard and soft segments and phase inversion were investigated. Increasing the hard segment content, i.e., average hard segment molecular weight, leads to an increase in the degree of micro-phase separation, hard domain order and crystallinity. The crystalline hard segment structures combined with the elastic nature of soft segment matrix provide enough physical and chemical crosslinks to have shape memory effect.
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4

Volodchenkov, A. D., Y. Kodera, and J. E. Garay. "Synthesis of strontium ferrite/iron oxide exchange coupled nano-powders with improved energy product for rare earth free permanent magnet applications." Journal of Materials Chemistry C 4, no. 24 (2016): 5593–601. http://dx.doi.org/10.1039/c6tc01300g.

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5

Fan, Quan Run, and Feng Pan. "Technology Mapping for Heterogeneous FPGA in Different EDA Stages." Applied Mechanics and Materials 229-231 (November 2012): 1866–69. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.1866.

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In traditional EDA flow, Technology mapping is performed after logic synthesis. Besides programmable logic blocks, heterogeneous FPGAs also have some hard blocks, such as memory block and multiplier, built in it. After logic synthesis, it will be difficult for technology mapping to find sub-circuits that can be implemented in hard blocks. In this paper, a systematic technology mapping approach is proposed. In the design phase, with the support of CAD tools, a module based design approach is used to map some design block to large hard blocks. During register transfer level synthesis, some functions that are suitable to be implemented in small hard blocks are identified. Other logic functions are mapped into lookup tables with different input size.
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6

Farzaliyev, V. M., and M. N. Aliyeva. "Feature analysis of vapor-phase chromatography of high boiler organic compounds." Azerbaijan Oil Industry, no. 4 (April 15, 2020): 40–47. http://dx.doi.org/10.37474/0365-8554/2020-4-40-47.

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The paper presents the physical-chemical features of the vapor-phase chromatography method for the analysis of polar high boiler organic compounds. The application conditions of vapor-phase chromatography for the research of petrochemical synthesis products are analyzed. The mechanism of chromatographic seperation of compounds in the vapor-liquid-solid phase system is reviewed. The physical-chemical parameters of application of vapor-phase chromatography are provided. It is shown that liquid crystals can be used for the efficiency increase of the analysis of high boiler organic compounds as hard carriers. Thus, isomer compounds in the flow of water steam may be seperated. The usage of water-formamide mixture as a gas carrier enables the analysis of high boiler amine-based organic compounds. Natural, modified zeolite-containing tuff, diatoms and zeolites can be used as adsorbents and hard carriers in the separation of high boiler products of petrochemical synthesis.
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7

NOMIZU, MOTOYOSHI, YOSHIMASA INAGAKI, TAKEYOSHI YAMASHITA, AKO OHKUBO, AKIRA OTAKA, NOBUTAKA FUJII, PETER P. ROLLER, and HARUAKI YAJIMA. "Two-step hard acid deprotection/cleavage procedure for solid phase peptide synthesis." International Journal of Peptide and Protein Research 37, no. 2 (January 12, 2009): 145–52. http://dx.doi.org/10.1111/j.1399-3011.1991.tb00095.x.

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8

Tavakolinia, Faezeh, Mohammad Yousefi, Seyyed Afghahi, Saeid Baghshahi, and Susan Samadi. "Synthesis of novel hard/soft ferrite composites particles with improved magnetic properties and exchange coupling." Processing and Application of Ceramics 12, no. 3 (2018): 248–56. http://dx.doi.org/10.2298/pac1803248t.

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SrFe12O19/Zn0.4Co0.2Ni0.4Fe2O4 hard/soft ferrite composite particles with 20, 40, 60 and 80 wt.% of soft phase were prepared by one-pot sol-gel auto-combustion and physical mixing methods. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM) were used to characterize the structural and magnetic properties of the samples. XRD spectrum revealed the formation of mixed ferrite phases in the composite particles. The hysteresis loops of the samples showed the presence of exchange coupling between the hard and soft ferrites. The composite particles with 20 and 60 wt.% of the soft phase demonstrated the highest Mr/Ms ratio, i.e. 0.29 and 0.28, respectively. In addition, the highest Ms, Mr and Hc were achieved in the composite particles with 40, 60 and 20 wt.% of the soft phase, respectively. Compared to the physical mixing method (PM), the composite particles prepared by the sol-gel auto-combustion method (OP) demonstrated better magnetic properties. The exchange coupling interaction between the hard and soft ferrite phases was similar in both methods. These composite particles exhibited magnetically single phase behaviour, however, the saturation magnetization was lower in the physical mixing pared to that of the one-pot method.
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9

Tang, Weiming, Richard J. Farris, William J. MacKnight, and Claus D. Eisenbach. "Segmented Polyurethane Elastomers with Liquid Crystalline Hard Segments. 1. Synthesis and Phase Behavior." Macromolecules 27, no. 10 (May 1994): 2814–19. http://dx.doi.org/10.1021/ma00088a023.

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10

Grass, Robert N., Stavros Tsantilis, and Sotiris E. Pratsinis. "Design of high-temperature, gas-phase synthesis of hard or soft TiO2 agglomerates." AIChE Journal 52, no. 4 (2006): 1318–25. http://dx.doi.org/10.1002/aic.10739.

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11

Popovich, A. A., V. N. Vasilenko, and V. P. Reva. "Formation of the phase composition of tungstenless hard alloy powder with mechanochemical synthesis." Soviet Powder Metallurgy and Metal Ceramics 31, no. 11 (November 1992): 920–22. http://dx.doi.org/10.1007/bf00797615.

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12

Jo, Nam Ju, Do Hee Lim, Young Min Song, Geong Mi Bark, and Won Ki Lee. "Synthesis and Properties of Polyurethane-Based Actuator with Poly(dimethyl Siloxane)." Materials Science Forum 620-622 (April 2009): 299–302. http://dx.doi.org/10.4028/www.scientific.net/msf.620-622.299.

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This paper investigated the use of electrostrictive polymers with compliant electrodes as a means of actuator. In many electrostrictive materials, especially polyurethane (PU) can produce large deformation and force because of its low elastic modulus.The electromechanical response is mainly due to Maxwell stress effect and electrostriction effect. When a thin film of dielectric elastomer is applied to an electric field, it will experience Maxwell stress caused by interactions of free charge between the electrodes and electrostriction caused by the reorientation of polar phase in the material. In this work, PU was composed of the soft segment with poly(dimethyl siloxane) (PDMS) and the hard segment with 4, 4’-diphenylmethane diisocyanate. Also the hard segment content of synthesized PU was controlled at 20, 25, 30, and 35wt%. To conclude, mechanical properties increased with the increase in hard segment contents. However actuation test showed that the deformation was decreased as hard segment contents increased.
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13

Jeong, Ji Hun, Hao Xuan Ma, Doyun Kim, Chang Woo Kim, In Ho Kim, Jae Woo Ahn, Dong Soo Kim, and Young Soo Kang. "Chemical synthesis of Nd2Fe14B hard phase magnetic nanoparticles with an enhanced coercivity value: effect of CaH2 amount on the magnetic properties." New Journal of Chemistry 40, no. 12 (2016): 10181–86. http://dx.doi.org/10.1039/c6nj02436j.

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Nd2Fe14B hard phase magnetic nanoparticles were successfully synthesized using a chemical synthesis route followed by a reduction and diffusion process without consuming a large amount of energy.
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14

Zhigalov, V. S., V. G. Myagkov, G. I. Frolov, L. E. Bykova, S. V. Komogortsev, G. N. Bondarenko, and V. I. Nizhankovskii. "Solid-State Synthesis of Co-Sm(110) Epitaxial Films with Large Magnetocrystalline Anisotropy." Solid State Phenomena 168-169 (December 2010): 188–91. http://dx.doi.org/10.4028/www.scientific.net/ssp.168-169.188.

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Solid-state synthesis of a Sm2Co7 (110) hard magnetic phase prepared by successive deposition of Co and Sm layers onto a MgO(001) surface at a temperature of 400 С has been experimentally studied. Upon annealing at 500 С, the structure of the material changes, which leads to the formation of an epitaxial Sm2Co17 (110) phase. The first and second magnetocrystalline anisotropy constants of the Co-Sm have been determined.
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15

Siljanovska Petreska, Gordana, Arantxa Arbe, Clemens Auschra, and Maria Paulis. "Mechanical and Morphological Properties of Waterborne ABA Hard-Soft-Hard Block Copolymers Synthesized by Means of RAFT Miniemulsion Polymerization." Polymers 11, no. 8 (July 30, 2019): 1259. http://dx.doi.org/10.3390/polym11081259.

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High molecular weight waterborne ABA block copolymers of styrene (St) and 2-ethylhexyl acrylate (2EHA) containing hard and soft domains were synthesized by means of RAFT (mini)emulsion polymerization using a bifunctional symmetric S,S-dibenzyl trithiocarbonate (DBTTC) RAFT agent. Miniemulsion polymerization was initially used for the synthesis of the A-block, which forms hard domains, followed by 2EHA pre-emulsion feeding to build the B-block soft domains. Polymerization kinetics and the evolution of the Molecular Weight Distribution (MWD) were followed during the synthesis of different ABA block copolymers. The thermal properties of the final symmetric block copolymers were studied on dried films by means of DSC. It was found that the block copolymers have two glass transitions, which indicates the presence of a two-phase system. Phase separation was investigated by means of microscopic techniques (AFM and TEM) and SAXS, both of the particles in the latex form, as well as after film formation at room temperature and after different post-treatments. Films were annealed at temperatures well above the glass transition temperature (Tg) of the hard phase to study the bulk morphology of the films after complete particle coalescence. Moreover, for comparison purposes, the films were re-dissolved in THF, and films were again cast directly from the homogeneous THF solutions. As THF is a good solvent for both blocks, such films serve as a reference for the equilibrium morphology. Finally, DMTA studies of the films annealed at different temperatures were performed to correlate the morphology changes with the mechanical properties of the block copolymers.
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16

Attfield, J. "New electronic perovskite oxides from beyond high pressure synthesis." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C615. http://dx.doi.org/10.1107/s205327331409384x.

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Materials synthesised from high pressure (HP) conditions offer a variety of possibilities for the discovery of new electronic and magnetic phenomena. Recovery of a solid to ambient pressure (AP) from its HP thermodynamic stability field effectively introduces a large negative pressure that can drive the material into an unusual electronic ground state; as illustrated by HP structural and property studies of PbRuO3 and BiNiO3. PbRuO3 is synthesised at 10 GPa and shows an orbitally ordered phase at AP and low temperatures that is suppressed at an apparent quantum critical point near 6 GPa [1]. A new structural phase emerges at much higher pressures ~30 GPa. BiNiO3 synthesised at 6 GPa shows an unusual charge order that is suppressed at 3.4 GPa; the transition is associated with a volume collapse leading to colossal negative thermal expansion [2]. Materials recovered from HP are also precursors for 'hard-soft' chemistry, where the instability of a dense precursor from `hard' HP conditions is relieved through `soft' post-synthesis modification. We recently demonstrated this concept for the HP phase SrCrO3 which on reduction gives two new phases SrCrO2.80 and SrCrO2.75 with long period oxygen vacancy, charge and spin ordered superstructures [3]. These studies have been carried out in collaboration with co-authors of the papers below.
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17

Liu, Maoyuan, and Lei Chen. "Research on Magnetic Property of Nd2Fe14B/α-Fe Nanocomposite Under Different Roller Speeds." Open Materials Science Journal 8, no. 1 (December 31, 2014): 127–30. http://dx.doi.org/10.2174/1874088x01408010127.

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Nano-composite permanent magnetic material is a new type of permanent magnetic material, and it is the synthesis of soft and hard magnetic phase within the nanoscale. On the basis of exchange coupling hard magnetizing theory, nano-composite permanent magnetic material can, at the same time, have high residual magnetization intensity of soft magnetic phase and high coercivity of hard magnetic phase, which can be developed into new generation high performance permanent magnetic material. Nevertheless, magnetic energy of permanent nano-composite magnet derived from experiments differs greatly from the theoretical value, and this is mainly due to fairly great difference between the micro-structure of material and the theoretical model. In this paper, the constituent was taken as (Nd, Pr, Dy)2(Fe, Nb)14B/α-Fe, and the fusant rapid quenching method was adopted to study the impact of different roller speeds on the magnetic property. Moreover, through the result of VSM, XRD and SPM, the magnetic property, phase composition and micro structure of alloy were analyzed.
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18

Dos santos-García, Antonio J., Elena Solana-Madruga, Clemens Ritter, David Ávila-Brande, Oscar Fabelo, and Regino Sáez-Puche. "Synthesis, structures and magnetic properties of the dimorphic Mn2CrSbO6oxide." Dalton Transactions 44, no. 23 (2015): 10665–72. http://dx.doi.org/10.1039/c4dt03849e.

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Mn2CrSbO6-perovskite was synthesized at high pressure in order to stabilize the small Mn2+cations on the A-perovskite site. Mn2CrSbO6-ilmenite polymorph can be prepared, starting from the perovskite, by a “hard-soft” phase transformation increasing the temperature at room pressure.
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19

Shen, Wei Hua. "Hard Template Route for Synthesis of Mesoporous Spinel Type Oxides with Ordered Structure." Advanced Materials Research 886 (January 2014): 200–203. http://dx.doi.org/10.4028/www.scientific.net/amr.886.200.

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The binary mesoporous spinel oxides with high surface area have been synthesized by using KIT-6 and SBA-15 as hard templates and hydrated nitrated salts as precursors. Low temperature such as 500 °C is suitable for preparation of NiCo2O4with spinel phase. High temperature such as 800 °C is necessary for preparation of NiMn2O4, MnCo2O4, and (Co0.5Mn0.5)3O4with pure spinel phase. The prepared mesoporous spinel shows high surface area as 43-105 m2/g with pore volume as0.095-0.233 cm3/g. It is preferred to form mesoporous NiCo2O4with spherical particles.
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20

Baker, Paul, Shane Catledge, Sumner Harris, Kathryn Ham, Wei-Chih Chen, Cheng-Chien Chen, and Yogesh Vohra. "Computational Predictions and Microwave Plasma Synthesis of Superhard Boron-Carbon Materials." Materials 11, no. 8 (July 25, 2018): 1279. http://dx.doi.org/10.3390/ma11081279.

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Superhard boron-carbon materials are of prime interest due to their non-oxidizing properties at high temperatures compared to diamond-based materials and their non-reactivity with ferrous metals under extreme conditions. In this work, evolutionary algorithms combined with density functional theory have been utilized to predict stable structures and properties for the boron-carbon system, including the elusive superhard BC5 compound. We report on the microwave plasma chemical vapor deposition on a silicon substrate of a series of composite materials containing amorphous boron-doped graphitic carbon, boron-doped diamond, and a cubic hard-phase with a boron-content as high as 7.7 at%. The nanoindentation hardness of these composite materials can be tailored from 8 GPa to as high as 62 GPa depending on the growth conditions. These materials have been characterized by electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray diffraction, and nanoindentation hardness, and the experimental results are compared with theoretical predictions. Our studies show that a significant amount of boron up to 7.7 at% can be accommodated in the cubic phase of diamond and its phonon modes and mechanical properties can be accurately modeled by theory. This cubic hard-phase can be incorporated into amorphous boron-carbon matrices to yield superhard materials with tunable hardness values.
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21

Chen, Xiao Dong, Tie Jun Ma, Hai Zhang, and Rong Sheng Chen. "Synthesis and Characterization of Novel Segmented Castable Polyurethanes Based on 2,4-TDI and 3,5-DMTDA." Applied Mechanics and Materials 29-32 (August 2010): 675–81. http://dx.doi.org/10.4028/www.scientific.net/amm.29-32.675.

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A series of three castable polyurethane elastomers were prepared from 2,4- toluene diisocyanate (TDI) and 3,5-dimethyl-thioltoluenediamine (DMTDA) chain extender, with polyethylene adipate (PEA), polyoxytetramethylene glycol (PTMG) and polycaprolactone (PCL) soft segments. The polyol molecular weight employed was 2000g/mol. The polyurethane elastomers were characterized by an electronmechanical universal testing machine, a LX-A Shore durometer and a Dynamic Mechanical analyzer (DMA). In addition, fractured surface of the polyurethane elastomers was investigated by a field emission scanning electron microscopy (FE-SEM). The test results showed PCL based elastomer exhibits the excellent tear and stress-strain properties that polyester based elastomers offer, while retaining superior resilience similar to polyether based elastomers. The static and dynamic properties of PCL based elastomer were more suitable for dynamic applications. SEM micrographs of all polyurethane samples indicated the existing of microphase separation structure. Particles of the dispersed phase formed by hard phase and crystalline part of the soft phase grow bigger with increasing crystallinity of the soft segments. The hard domains are irregular shapes and with size of a few micrometers.
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22

Wu, Yi, Chuan Qiang Yin, Zheng Guang Zou, Xiao Min Li, Yu Fang Shen, and Lang Zhou. "Steel-Bonded Cemented Carbide GT35 by In Situ Reduction of Natural Ilmenite." Key Engineering Materials 336-338 (April 2007): 1390–93. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.1390.

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Steel-bonded cemented carbide GT35 was fabricated from natural ilmenite by in-situ synthesis and vacuum pressureless sintering. The thermodynamics of the synthesis process were analyzed. The results indicated that the stable phases were TiC and iron in the FeTiO3-C system. During the synthesis process, ilmenite was reduced by graphite via a series of titanium oxides to obtain hard phase (TiC) and the steel matrix as the ultimate products. The experimental results shown that GT35 had a reasonable phase composition and fine TiC particles embedded uniformly in the steel matrixes. The composites exhibited excellent mechanical properties: the relative density was higher than 97%, the hardness reached HRC 61.5 and the maximal bending strength was about 1270MPa.
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23

Jadhav, Abhijit P., Abid Hussain, Jae Ho Lee, Youn Kyung Baek, Chul Jin Choi, and Young Soo Kang. "One pot synthesis of hard phase Nd2Fe14B nanoparticles and Nd2Fe14B/α-Fe nanocomposite magnetic materials." New Journal of Chemistry 36, no. 11 (2012): 2405. http://dx.doi.org/10.1039/c2nj40620a.

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24

Smetanina, K. E., P. V. Andreev, E. A. Lantsev, M. M. Vostokov, and N. V. Malekhonova. "X-ray diffraction layer-by-layer analysis of tungsten carbide-based hard alloys." Industrial laboratory. Diagnostics of materials 86, no. 8 (August 14, 2020): 38–42. http://dx.doi.org/10.26896/1028-6861-2020-86-8-38-42.

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Improvement of the physical and mechanical properties of hard alloys based on WC – Co widely used in manufacturing of structural and tool products nowadays results from the use of novel technologies providing formation of a homogeneous high-density structures. Slight deviations of the carbon content from the equilibrium state lead to the formation of brittle η-phases (in particular, Co3W3C) and, accordingly, to deterioration of the mechanical properties of the product. We present the results of studying the homogeneity of the phase composition of the samples of hard alloys WC + 10% Co, obtained using advanced technologies of plasma-chemical synthesis and spark plasma sintering (SPS). The layer-by-layer X-ray phase analysis revealed the heterogeneity of the phase composition in depth: the brittle η-phase (Co3W3C) appears at a depth of ≥100 μm and reaches a constant value of 18 ± 1 wt.% at >200 μm, which indirectly confirms the hypothesis of carbon diffusion from graphite punches contacting with the surface of sintered samples and makes it possible to expand the range of parameters affecting the process of spark plasma sintering.
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Kuzyura, Anastasia, Tatiana Setkova, Dmitriy Chareev, Anna Spivak, Ekaterina Kozlyakova, Valentin Osadchii, Mikhail Voronin, and Evgeniy Osadchii. "Experimental Methods of Synthesis of Nano-/Macro Mineral Materials." Advanced Materials Research 650 (January 2013): 308–13. http://dx.doi.org/10.4028/www.scientific.net/amr.650.308.

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This work is devoted to development of synthesis methods of nano- and macrofunctional materials for industry, electronics, and modern science and technology. The authors have developed advanced methods of obtaining various carbon, silicate and chalcogenide materials by melt and hydrothermal methods with using of optimized chemical and thermodynamic parameters of synthesis. As a result a new super hard material - carbonate-synthetic diamond polycrystals were obtained. Nanodiamonds were synthesized by direct conversion of graphite into diamond. New species of macro- and fine crystalline piezoelectric tourmaline containing 3d-elements were produced by hydrothermal method. Using a flux technique the single crystals of different chalcogenide phase with unique superconducting properties were grown.
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Wang, Y. G., Di Zhang, and Ming Chen. "Development of Coating Material by In Situ Reaction Synthesis." Key Engineering Materials 353-358 (September 2007): 1696–99. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.1696.

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A type of wear resistance coating material composed by ternary-boride-based (TBB) cermet coating and steel 65Mn substrate has been developed successfully by in-situ reaction synthesis. The TBB cermet coating has been formed by the in-situ reactions among the mixed raw metal powders during the process of casting. Microstructure has been studied using X-Ray Diffraction (XRD) and scanning electron microscopy (SEM). Results show that the main composition of the coating is ternary boride base hard phase Mo2FeB2 and ferrous base binder phase α-Fe, both of them distribute uniformly in the coating. There is element diffusion in the interface of coating and steel substrate. The bonding at the interface of coating and steel substrate is excellent which has been confirmed by the three-point bend tests.
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27

Chkhartishvili, Levan, Levan Antashvili, Lasha Dalakishvili, Roin Chedia, Otar Tsagareishvili, and Archil Mikeladze. "On Modeling of Synthesis Process of Boron Carbide Based Nanocomposites." Condensed Matter 6, no. 1 (January 18, 2021): 3. http://dx.doi.org/10.3390/condmat6010003.

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Nanocomposites based on boron carbide B4C are hard materials with wide field of applications in modern technologies. A system of first-order ordinary differential equations that simulates the process of chemical synthesis of nanopowders of B4C–TiB2 compositions containing titanium diboride (TiB2) as an additional phase is suggested and resolved numerically for a typical ratio of reaction constants. Reagents and products concentrations are found as time-functions. In this way, the optimal route of production technology of boron carbide-based nanomaterials can be identified.
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28

Rasli @ Rosli, Nur Athirah, and Syazana Ahmad Zubir. "Synthesis and Characterization of Palm Kernel Oil Polyol Based Shape Memory Polyurethane: Effect of Different Diisocyanates." Key Engineering Materials 908 (January 28, 2022): 14–19. http://dx.doi.org/10.4028/p-l49hs4.

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Shape memory polyurethane (SMPU) is a very versatile material that has a broad array of applications. The selection of soft segments and hard segments play critical roles in determining the structure-property behaviors of SMPU. This research was conducted to evaluate the role of distinct types of diisocyanate on the final properties of polyurethane (PU). Palm kernel oil polyol (PKO) based PU were produced by using two-step bulk polymerization method with variations of diisocyanates. Isophorone diisocyanate (IPDI), 4,4-methylenebis (cyclohexyl isocyanate) (HMDI) and hexamethylene diisocyanate (HDI) were used in the preparation of PU and the soft segment crystallinity, thermal and shape memory properties of the PU were evaluated. Based on the analyses, it was found that different types of diisocyanate and combination of diisocyanates had huge impact on the properties of the synthesized PU. The Fourier transformation infrared (FTIR) analysis revealed that IPDI based PU achieved the highest hydrogen bonding index value which promoted the phase separation. This is in accordance with differential scanning calorimetric (DSC) and x-ray diffraction (XRD) analysis which showed that IPDI based PU exhibited crystalline soft phase, hence resulted in an excellent shape fixity behavior. On the other hand, HDI and HMDI based polyurethane prepared showed absence of crystalline soft phase based on the DSC thermogram and XRD diffractogram. These results suggest the phase mixing phenomenon between soft and hard segments which contributed to low shape memory behavior of the resulting polyurethane.
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29

SUN, LU, HAO CHEN, and BO LIU. "SURFACE MODIFICATIONS WITH LASER SYNTHESIZED Mo MODIFIED COATING." Surface Review and Letters 20, no. 01 (February 2013): 1350003. http://dx.doi.org/10.1142/s0218625x13500030.

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Mg–Cu–Al was first used to improve the surface performance of TA15 titanium alloys by means of laser cladding technique. The synthesis of hard composite coating on TA15 titanium alloy by laser cladding of Mg–Cu–Al–B4C/Mo pre-placed powders was investigated by means of scanning electron microscope, energy dispersive spectrometer and high resolution transmission electron microscope. Experimental results indicated that such composite coating mainly consisted of TiB2 , TiB , TiC , Ti3Al and AlCuMg . Compared with TA15 alloy substrate, an improvement of wear resistance was observed for this composite coating due to the actions of fine grain, amorphous and hard phase strengthening.
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Haq, Muhammad Aneeq, Han-Saem Lee, Mi Hye Lee, Da-Woon Jeong, Eom Nu Si A, Bin Lee, Yoseb Song, and Bum Sung Kim. "Nd2Fe14B/FeCo Core–Shell Nanoparticle Synthesis Using Galvanic Substitution Based Electroless Plating." Coatings 12, no. 3 (March 15, 2022): 389. http://dx.doi.org/10.3390/coatings12030389.

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Core–shell structured magnetic nanoparticles combine hard and soft phases to improve energy efficiency. The mutual interaction of the two phases can lead to the exchange spring effect, leading to higher magnetic energy. In this regard, synthesis of Nd2Fe14B-based core–shell-structured powders have proven to be elusive, due to the relatively reactive nature of this phase. In this study, a process has been established for successfully coating the surface of Nd2Fe14B powders with a FeCo layer using the galvanic displacement method. Initially, a binary phase magnetic powder was synthesized containing Nd2Fe14B and Nd2Fe17 phase. Subsequently, the powders were coated using a Co precursor at 303 K. During coating, the metastable Nd2Fe17 phase was dissolved, and the Fe ions were released into the solution. Subsequently, the Fe ions deposited together with the Co ions on the surface of Nd2Fe14B powder to form a FeCo shell. The deposited layer thickness and composition was confirmed using TEM analysis.
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Li, Yang, Ming Xian Liu, Li Hua Gan, Liang Yang, Zi Jie Xu, Xiao Gang Wang, and Long Wu Chen. "Double Templating Synthesis and Electrochemical Properties of Carbon Foams." Advanced Materials Research 347-353 (October 2011): 3400–3403. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.3400.

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In this paper, we demonstrated the synthesis and electrochemical properties of carbon foams for use as supercapacitor electrode materials. Carbon foams were prepared by double templating method in which emulsion and nanosilica were used as soft template and hard template, respectively. By using Span 80 and Tween 80 as emulsifiers, resorcinol/formaldehyde aqueous solution which contained nanosilica as aqueous phase and 1iquid paraffin as oil phase, an O/W emulsion was obtained. Carbon foams were obtained by emulsion polymerization, carbonization and the subsequent removal of the hard template. The as-prepared carbon foams were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analyzer, and electrochemical workstation. The results indicate that the resultant carbon foams have specific surface area of 160 m2/g, total pore volume of 0.15 cm3/g and possess dual pore size distributions with macropore sizes of 0.5-2.0 μm and the most probable pore size of 4.1 nm. The electrochemical properties of the carbon foams have been investigated by cyclic voltammetry (CV) and galvanostatic charge- discharge with a three-electrode system in electrolyte of 6 mol/L KOH solution. The CV curves of the carbon foams show rectangular-like shape without obvious oxidation-reduction evolution peak, which suggests a typical nonfaradic adsorption/desorption reaction. The carbon foams present linear galvanostatic charge-discharge curve under the current densities of 1.0-5.0 A/g and their specific capacitance values are 60-90 F/g. The good electrochemical performances of carbon foams would provide candidate as electrode materials for supercapacitors.
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32

Niu, Jin Long. "Hydrothermal Synthesis of Nano-Crystalline Hydroxyapatite." Key Engineering Materials 330-332 (February 2007): 247–50. http://dx.doi.org/10.4028/www.scientific.net/kem.330-332.247.

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Natural biological hard tissues are nanocomposites of proteins and calcium hydroxyapatite (HAp) with superior strength and bioresorbabilities. Nanometer scale hyroxyapatite is the key material to manufacture bioresorbable bone substitute. An attempt was conducted to synthesis nano-crystalline hydroxyapatite with a hydrothermal chemical method. The prepared nano-crystalline HAp was characterized for its phase purity and nanoscale morphological structure by XRD, TEM and FTIR. The obtained results indicated that hydrothermal synthesized nano-crystalline HAp was pure single phased HAp with a diameter of 20 to 50nm and length range between 50 to 200nm and each HAp particle was observed to be a monocrystal of HAp. It’s suggested that hydrothermal treatment may be an effective method to get pure and nice crystallized nano-sized stoichiometric hydroxyapatite.
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33

Maletaskic, Jelena, Bratislav Todorovic, Martina Gilic, Milena Marinovic-Cincovic, Katsumi Yoshida, Anna Gubarevich, and Branko Matovic. "Synthesis and characterization of monophase CaO-TiO2-SiO2 (sphene) based glass-ceramics." Science of Sintering 52, no. 1 (2020): 41–52. http://dx.doi.org/10.2298/sos2001041m.

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Sphene based glass-ceramics (CaTiSiO5), an excellent candidate for a host lattice of ceramic materials and for nuclear waste immobilization, has been prepared from a powder mixture of CaCO3, TiO2 and SiO2 using vibro-milling for homogenization. Starting powders were melted at 1400?C for 2 h, cooled to room temperature, grounded again, then crystallized by thermal treatment yielding a sphene glass-ceramic. The evolution of the phase composition during thermal treatment was investigated by X-ray powder diffraction (XRPD), FT-IR, Raman and thermal analyses (TG-DTA). Pure synthetic single phase sphene was formed at 800?C for 4 h, even it is very hard to obtain monophase powder at such low temperature. Powder morphology was analyzed by scanning electron microscopy (SEM).
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34

Minaev, Y. A. "Diamond Like Structure Nano Carbonitrides Hardening of Hard Alloys Cutting Tools." Advanced Materials Research 428 (January 2012): 65–68. http://dx.doi.org/10.4028/www.scientific.net/amr.428.65.

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The fundamental property of solid crystalline materialsi.e.phenomena of first-order phase transition of grain boundaries with formation of two-dimensional liquid have been used for elaboration of the new technology. Nitriding type methods have been used to develop strategies for effective forming of coatings by synthesis of nitrides and carbonitrides on surface layers of hard metals. WC-Co and WC-TiC-Co hard metal tools have been used for experiments. Industrial tests indicated that the tools functional properties improved 2-9 times. The new tools demonstrated a high resistance to surface wear and to fragile break–down. The formed layers, interface and binder behaviour have been investigated through the experiments with use of optic and electron microscope, X-ray phase analysis and micro-hardness device measures. The layer microstructure investigation demonstrates: the hardening of thin surface layer (0.1-0.3 mm) by nanosize carbonitrides with diamond like structure and strengthening of the following layer by recristallization of W carbides grains and by formation of coherent structure in Co-binder.
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35

Kawamura, Yasuhiko, Yasuyuki Akai, and Masao Tsukayama. "Combinatorial Synthesis of Exohedrally Modified Fullerene Derivatives." International Journal of Modern Physics B 17, no. 08n09 (April 10, 2003): 1910–15. http://dx.doi.org/10.1142/s0217979203019861.

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Fulleropyrrolidines have been very welcomed in a community of a fullerene science. But sometimes the synthesis ends up with disappointing yields of the products. In order to overcome the problem and to explore more environmentally benign method for synthesizing fullerene derivatives having various attachment on the surface of the fullerenes, a solid-phase synthesis is examined. We found that the dipolar cycloaddition of an azomethine ylide, i.e., 2-phenyl-N-benzylideneglycine methyl ester, supported on a Wang resin, proceeded feasibly with C 60 and the objective fulleropyrrolidines were afforded in good yields (>75%). The method is expected to be utilized with wide range of application and it is therefore able to provide a compound library of modified fullerenes which is hard to obtain by other methods employed so far.
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36

Lew, Kien Seng, Radzali Othman, and Fei Yee Yeoh. "Synthesis and Characterization of Mesoporous Hydroxyapatite." Advances in Science and Technology 63 (October 2010): 152–57. http://dx.doi.org/10.4028/www.scientific.net/ast.63.152.

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Among the porous media, hydroxyapatite (HA) possesses good biocompatibility and bioactivity properties with respect to bone cells and tissues, due to its similarity with the hard tissues of the body. In this study, mesoporous HA was synthesized using a soft-templating technique via a self-assembly between HA and cationic surfactant decyltrimethylammonium bromide (C10TAB), which is analogous to the synthesis of mesoporous silica MCM-41. This co-precipitation method involved formation of hexagonal-phase micelle template by the surfactant and the precipitation of HA surrounding the micelle. After ageing, calcination was carried out to remove the templates, revealing the pores as well as to produce more crystalline and more stable HA structure. This study showed that instead of hexadecyltrimethylammonium bromide (C16TAB) which was conventionally used, C10TAB could also be used to synthesize single-phase mesoporous HA with pore size ca. 3 nm. Ageing temperature of 120 °C, for 24 hours was found sufficient for the formation of mesoporous HA. The adsorption properties of mesoporous HA was able to be improved by increasing the water content of C10TAB-phosphate solution and by constant pH adjustment during the mixing of solutions.
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37

Nguyen, Tien Anh, Thanh Le Pham, Irina Yakovlevna Mittova, Valentina Olegovna Mittova, Truc Linh Thi Nguyen, Hung Van Nguyen, and Vuong Xuan Bui. "Co-Doped NdFeO3 Nanoparticles: Synthesis, Optical, and Magnetic Properties Study." Nanomaterials 11, no. 4 (April 6, 2021): 937. http://dx.doi.org/10.3390/nano11040937.

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In this work, single-phase nanostructured NdFe1−xCoxO3 (x = 0, 0.1, 0.2, and 0.3) perovskite materials were obtained by annealing stoichiochemistry mixtures of their component hydroxides at 750 °C for 60 min. The partial substitution of Fe by Co in the NdFeO3 crystal lattice leads to significant changes in the structural characteristics, and as a consequence, also alters both the magnetic and optical properties of the resulting perovskites. The low optical band gap (Eg = 2.06 ÷ 1.46 eV) and high coercivity (Hc = 136.76 ÷ 416.06 Oe) give Co-doped NdFeO3 nanoparticles a huge advantage for application in both photocatalysis and hard magnetic devices.
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38

Wang, Jilin, Lulu Zhang, Fei Long, Weimin Wang, Yunle Gu, Shuyi Mo, Zhengguang Zou, and Zhengyi Fu. "Solvent-free catalytic synthesis and optical properties of super-hard phase ultrafine carbon nitride nanowires with abundant surface active sites." RSC Advances 6, no. 28 (2016): 23272–78. http://dx.doi.org/10.1039/c6ra02475k.

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39

Costa, G. C. C. da, and R. Muccillo. "Synthesis of Lanthanum Beta Alumina by the Polymeric Precursor Technique." Materials Science Forum 530-531 (November 2006): 649–54. http://dx.doi.org/10.4028/www.scientific.net/msf.530-531.649.

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Lanthanum beta alumina powders were obtained by the polymeric precursor technique using lanthanum nitrate, aluminum nitrate, ethylene glycol and citric acid. The transformations that occur during thermal treatment of the precursor solution were evaluated by thermogravimetric and differential thermal analysis. Fourier Transform Infrared analysis for residual carbon qualitative detection and gas adsorption analysis for evaluating specific surface area, BET method, were carried out in powder specimens heat treated at different temperatures. High calcination temperature leads to the formation of hard agglomerates. The powders calcined at 800°C for 4 h have high specific surface area, ~ 120 m2/g. All processed powders and green pellets sintered at different temperatures were analyzed by X-ray diffraction for structural phase determination. Single phase LaAl11O18 pellets have application as solid electrolytes in disposable electrochemical devices for monitoring dissolved oxygen species in molten steel at very high temperatures, > 1500 °C, during steel production.
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40

NOMIZU, MOTOYOSHI, YOSHIMASA INAGAKI, AKIHIRO IWAMATSU, TOMOKO KASHIWABARA, HIDEO OHTA, AKIHITO MORITA, KOJI NISHIKORI, AKIRA OTAKA, NOBUTAKA FUJII, and PETER P. ROLLER. "Solid phase peptide synthesis of human endothelin precursor peptide using two-step hard acid deprotection/cleavage methods." International Journal of Peptide and Protein Research 38, no. 6 (January 12, 2009): 580–87. http://dx.doi.org/10.1111/j.1399-3011.1991.tb01543.x.

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41

Jalabadze, Nikoloz, Lili Nadaraia, and Levan Khundadze. "SPS Method for Manufacturing Carbide Materials." Applied Mechanics and Materials 376 (August 2013): 38–41. http://dx.doi.org/10.4028/www.scientific.net/amm.376.38.

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Due the rapid heating rate combined with high pressure by the Spark Plasma Sintering (SPS) technologies possible manufacture a wide range of novel materials with exceptional properties that cannot be achieved using conventional sintering techniques. Hard metals are, from a technical point of view, one of the most successful composite materials. An overview of the metallurgical reactions during the SPS sintering process of powder mixtures for the manufacture of hard metals is presented. The relatively complex phase reactions in the multi-component system TiC-Mo-W-Ni are discussed. There were elaborated a new technology for the fabrication of nanocrystalline hard metals of a new class assigned for the production of articles with high different characteristics. Elaborated materials are characterized by high melting temperature, hardness, wear-resistance, and satisfactory strength at high temperature and corrosive resistance. Through the use of developed technology and the appropriate structural condition gives possibility to achieve high physical-mechanical characteristics. Obtaining of composite materials via elaborated technology is available from the corresponding complex compounds and directly consisting elements too. In this case High-temperature Self-propagation Synthesis (SHS) and spark plasma sintering/synthesis (SPS) process are united and during a single operation it is possible to get not only the powder materials but at the same time obtain required details.
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42

Kalisz, Grzegorz, Ewa Grzanka, Dariusz Wasik, Anna Swiderska-Sroda, Stanislaw Gierlotka, Jolanta Borysiuk, Maria Kaminska, Andrzej Twardowski, and Bogdan F. Palosz. "Fabrication and Physical Properties of SiC-GaAs Nano-Composites." Solid State Phenomena 114 (July 2006): 297–302. http://dx.doi.org/10.4028/www.scientific.net/ssp.114.297.

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Nano-composites consisting of a primary matrix phase of hard nanocrystalline SiC and a secondary nanocrystalline GaAs semiconductor phase were obtained by high-pressure zone infiltration. The synthesis occurs in three stages: (i) at room- temperature the SiC nanopowder is compacted under high pressure to 8 GPa, (ii) the temperature is increased to 1240°C, above the melting point of GaAs, and the pores were filled with liquid, (iii) on cooling GaAs nanocrystallites grow in the pores. The synthesis was performed using a toroid-type high-pressure apparatus (IHPP PAS, Warsaw) and a six anvil cubic press (MAX80 at HASYLAB, Hamburg). X-ray diffraction studies were performed with a laboratory D5000 Siemens diffractometer. The phase compositionn, grain size and macrostrains in the synthesized materials were examined. The microstructure of the composites was characterized using a Scanning Electron Microscopy (SEM), and High Resolution Transmission Electron Microscopy (TEM). Far-infrared reflectivity and Raman spectroscopy measurements were used to trace built-in strains.
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43

Minaev, Y. A. "Fundamental Property of Metals – Grain Boundaries Phase Transition as a Basis of Nanostructured Layers, Materials and Composites Production." Materials Science Forum 654-656 (June 2010): 1852–55. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.1852.

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The obtained generalized equation for description of a fundamental property of solid crystalline materials i.e. first-order phase transition of the grain boundaries with formation of two-dimensional liquid has been used for calculating of transition temperature of any metals, which value lies in range 0.55 – 086 of melting point. Based on these conclusions to develop strategies for effective forming of coatings by synthesis of nitrides and carbonitrides on surface layers of hard metals and chromium steels have been made. It was shown the hardening of thin surface layer (0.1-0.5mm) due enriched of a nitrides in steels and carbonitrides with diamond like structure and strengthening the following layer by recristallization of W carbides in WC-Co and WC-TiC-Co hard metal. These result to increase of alloys hardness, ductility, and resistance to wear and decrease of sensibility to fragile rupture. Industrial tests have been made.
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44

Yang, Lian Wei, Rui Jie Wang, Yun Dong, and Xiao Ping Lin. "Synthesis of Fine Co/ WC Composite and Application to Supersonic Plasma Spraying." Advanced Materials Research 454 (January 2012): 110–13. http://dx.doi.org/10.4028/www.scientific.net/amr.454.110.

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Co/ WC composite powders (with 10 wt% content of Co) were synthesized by direct mechanical grinding in a rotary-vibration mill. The powders with different mill time were evaluated. WC and WC/Co composite coatings were prepared by supersonic plasma spraying. The results showed that the milled powders consist of composite particles that were formed in the first 2h of milling. Longer milling times improve the distribution of phases inside the composite particles. The formation of the composite particles involves sequential steps of deformation, fragmentation, cold welding, work hardening and piercing of particles of the hard phase in the soft phase. X-ray spectra of the sprayed coating are shown that only very weak W2C and Co6W6C peaks are observed. Compared with WC coating, the Co/ WC coating is denser, and less large pores within composite coating.
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45

Dojcinovic, Biljana, Vesna Antic, Marija Vuckovic, and Jasna Djonlagic. "Synthesis of thermoplastic poly(ester-siloxane)s in the melt and in solution." Journal of the Serbian Chemical Society 70, no. 12 (2005): 1469–85. http://dx.doi.org/10.2298/jsc0512469d.

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Two series of thermoplastic elastomers, based on poly(dimethylsiloxane) PDMS, as the soft segment and poly(butylene terephthalate), PBT, as the hard segment, were synthesized by catalyzed transesterification, from dimethyl terephthalate, DMT, silanol-terminated poly(dimethylsiloxane), PDMS-OH Mn=1750g/mol, and 1,4-butanediol, BD. The mole ratio of the starting comonomers was selected to result in a constant hard to soft weight ratio of 55:45. The first series was synthesized in order to determine the optimal mole ratio of BD and DMT for the synthesis of high molecular weight thermoplastic poly(ester-siloxane)s, TPESs. The second series was performed in the presence of the high-boiling solvent, 1,2,4-trichlorbenzene in order to increase the mixing between the extremely non-polar siloxane prepolymer and the polar reactants, DMT and BD, and, therefore, avoid phase separation during synthesis. The structure and composition of the synthesized poly(ester-siloxane)s were verified by 1H-NMR spectroscopy, while the melting temperatures and degree of crystallinity were determined by differential scanning calorimetry (DSC). The effectiveness of the incorporation of the silanol-terminated poly( dimethylsiloxane) into the polyester chains was verified by chloroform extraction. The rheological properties of the poly(ester-siloxane)s were investigated by dynamic mechanical spectroscopy (DMA).
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46

Rafitasari, Yeti, Ardita Septiani, Asep Ridwan Nugraha, Ervin Naufal Arrasyid, Dedi, and Agustinus Agung Nugroho. "Synthesis of Bismuth Ferrite and its Application for Oscillator Material up to 25 GHz Range." Materials Science Forum 1028 (April 2021): 9–14. http://dx.doi.org/10.4028/www.scientific.net/msf.1028.9.

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Among other multiferroic materials, bismuth ferrite (BiFeO3) attracts much attention due to its room-temperature properties and its wide potential applications. However, the synthesis to obtain a single-phase material is hard to be achieved because of the volatility of bismuth oxide. In this study, the BiFeO3 powders were synthesized by using a sol-gel method from the nitrates of bismuth and iron salt with the various stoichiometric ratios between Bi and Fe of 1:1.02, 1:1, 1.02:1, and 1.03:1. The single-phase and a good stoichiometric ratio of Bi: Fe = 1:1 was obtained from the starting composition ratio of 1.03:1 with a quenching process from 550°C sintering temperature. The single-phase of BiFeO3 shows a hysteresis curve of a weak antiferromagnetic with a coercive field of about 1.38 kOe at room temperature. The measurement of microwave oscillator was measured by using a dielectric resonator from 0 to 25 GHz does not show any resonant peak.
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47

Zhao, Hong, Shi Wei Yang, Ying Jie Qiao, and Xing Hong Zhang. "Wear-Resistant Properties of TiC/Fe Ceramic Composite Coating on Steel Plate via Combustion Synthesis." Advanced Materials Research 105-106 (April 2010): 435–37. http://dx.doi.org/10.4028/www.scientific.net/amr.105-106.435.

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The highly dense TiC/Fe ceramic coating was fabricated on Q235 steel surface by self- propagating high-temperature synthesis combined with pseudo hot iso-static pressing. The wear-resistant properties were examined by means of ball-on-disk contact wear test. The microstructure of TiC/Fe cermets coating was investigated. The results show that TiC/Fe cermets coating has an excellent wear-resistant property. There is little mass loss after 1200s under 30N loading under the condition of dry sliding wear testing. The major wear mechanisms are described by the following stages: sticking friction, grain abrasion and stripping of hard phase.
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48

Fu, Peng, Peng Xi, Fu Lai Zhao, and Bo Wen Cheng. "Synthesis and Properties of a Novel Environmentally Friendly Phase Change Energy Storage Coating Additive." Advanced Materials Research 805-806 (September 2013): 1538–41. http://dx.doi.org/10.4028/www.scientific.net/amr.805-806.1538.

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Waterborne polyurethane (PU) coatings are diluted with water as the medium, without volatile organic solvents and harmful to human body and environment. Adding insulation materials in building individually is a waste of resource. We found a kind of waterborne PU phase change energy storage material easily dissolved and formed film after solvent evaporating having the potential of coating. In this article, we synthesized a new kind of waterborne PU phase change energy storage coating additive via two-step synthesis method, of which a new type of aromatic tetrahydroxycompound (ATTC) is used as branch unit, 4, 4'-diphenylmethanediisocyanate (MDI) and polyethylene glycol (PEG) respectively as hard and soft segments. POM photographs show that the sphaerocrystals of this new coating additive can reach 200-500μm. The crystal structure is characterized by XRD, and the phase change unit is PEG. DSC tests show that the phase change enthalpy value of this coating additive is very high reached more than 90 J/g. The preservation of this water-soluble PU coating is relatively simple, using water as solvent, which can be easy to dissolve in water and form film after water evaporated.
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49

León-Patiño, Carlos A., Deisy Ramirez-Vinasco, Ena A. Aguilar-Reyes, and Makoto Nanko. "Synthesis and Properties of Pulsed Electric Current Sintered AlN/Cu Composites." MRS Advances 3, no. 62 (2018): 3611–19. http://dx.doi.org/10.1557/adv.2018.671.

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ABSTRACTThis research shows the development of alternative Cu-based materials for applications where enhanced thermal properties are desired. Cu/AlN composites were fabricated from mixtures of pure Cu and copper plated AlN-Cu composite powders. The ceramic phase was added in amounts of 10, 20 and 30 vol.% and the mixtures sintered by pulsed electric current sintering process (PECS). The results showed that the AlN particles are homogeneously distributed in the copper matrix and that the true contacts between hard particles are reduced because of the deposited copper on their surfaces, improving the connectivity of the matrix phase and bonding at the metal-ceramic interface. The relative density of the Cu/AlN composites was major than 97% in all cases. Thermal conductivity of the composites was high and decreased with the ceramic content from 359 to 194 W/mK, for 10 and 30% AlN, respectively. The coefficient of thermal expansion followed a lineal behavior with temperature and is also reduced with the ceramic content.
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Zhu, Rong, Zong Rui Zhang, Ming Bei Zhu, and Xin Yu Wang. "Synthesis and Characterization of Biomedical Aliphatic Polyurethane Material." Materials Science Forum 809-810 (December 2014): 520–26. http://dx.doi.org/10.4028/www.scientific.net/msf.809-810.520.

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Biomedical transparent poly(carbonate-urethane) elastomers were synthesized by melting pre-polymer method, using 4,4’-methylenebis (cyclohexyl isocyanate)(H12MDI) and chain extender (butadiene)(BDO) as hard segment, poly(1,6-hexanediol) carbonate diols(PCDL) as soft segment, and dibutyltin dilaurate as catalyst.The effects of molar ratio of the reactants on mechanical properties of PCU were studied and the relationship between micro-phase separation structure and properties was analyzed by the contact angle determination, total reflection fourier transform infrared spectrography(ATR-FTIR), differential scanning calorimeter(DSC),gel permeation chromatograph (GPC), mechanical property test. The comparative analysis was made between the prepared material and commercial medical polyurethane materials, showing the prepared poly(carbonate-urethane) elastomers was better in mechanical properties. As a elastic biomedical material, it has a great potential for developments and applications in biomedical materials.
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