Gotowe bibliografie tematyczne / Co-base alloys

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Gotowa bibliografia na temat „Co-base alloys”

Autor: Grafiati

Data publikacji: 6 września 2023

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Artykuły w czasopismach na temat "Co-base alloys"

Podhorná, Božena, Irena Andršová, Jana Dobrovská, Vlastimil Vodárek i Karel Hrbáček. "Structure Stability of Ni-Base and Co-Base Alloys". Materials Science Forum 782 (kwiecień 2014): 431–36. http://dx.doi.org/10.4028/www.scientific.net/msf.782.431.

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This article summarises results of structure stability investigation of cast Ni-base and Co-base alloys after prolonged high temperature exposure at 900-1100 °C. Cast Ni (Co)-Cr-W-C alloys are resistant to high-temperature corrosion, due to high chromium content. Their heat resistance is caused by presence of carbides, which are stable at very high temperatures. Carbides precipitate in shape of large plate-like particles or carbide eutectics at casting cell boundaries, thus forming carbide skeleton of the alloy. Carbide morphology and temperature stability depends on chemical composition of the alloy, e.g. carbide content, type and content of carbide-forming elements. Microstructure changes were evaluated by stereological analysis and X ray-spectral microanalysis.

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Sahay, S. K., i B. Goswami. "Recent Developments in Co-Base Alloys". Solid State Phenomena 150 (styczeń 2009): 197–219. http://dx.doi.org/10.4028/www.scientific.net/ssp.150.197.

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Cobalt base alloys are being designed and developed to produce the best possible combinations of high temperature properties. Existence of martensite forms consisting of various intermetallic compounds has been described along with the variables associated with fcc-hcp transition at respective conditions of formation. Achievements of cobalt base alloys have been primarily due to various thermodynamic and kinetic parameters for most suitable combinations of alloying. The phase transformations in this review include the study of defect structure, martensite transformation, order-disorder kinetics, and recrystallization and grain growth mechanisms. The improvements in mechanical properties stem from the contribution of additional alloying elements to discontinuous precipitation, diffusion mechanism at grain boundaries and changes in compressive strength, yield strength, elongation and brittleness. L12-compound in cobalt base alloys possesses an important identity, which changes the characteristics of usable compositions.

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Makineni, Surendra Kumar, Mahander Pratap Singh i Kamanio Chattopadhyay. "Low-Density, High-Temperature Co Base Superalloys". Annual Review of Materials Research 51, nr 1 (26.07.2021): 187–208. http://dx.doi.org/10.1146/annurev-matsci-080619-014459.

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Co base superalloys strengthened by coherent L12 ordered γ′ precipitate in a disordered face-centered cubic γ matrix represent a new opportunity for high-temperature alloy development. The emergence of alloys with low density and high specific yield strength at elevated temperatures has further energized the research and development efforts in the last 5 years. Initially stabilized by the addition of small amounts of Nb and Ta, these new generations of alloys with multiple alloying additions to form basic quaternary and ternary alloys have steadily expanded the property envelopes to raise hope for a modern class of superalloys with higher-temperature capabilities. This article reviews the work of a vibrant set of researchers across the globe whose findings are constantly unlocking the potential of these alloys. These developments have achieved high-temperature strength (at 870°C) >0.6 GPa, γ′ solvus temperature exceeding 1,100°C, and densities between 7.8 and 8.6 g/cm3.

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Takezawa, Kazuhiro, Shigeharu Ukai i Shigenari Hayashi. "Microstructure Control of Co-Base ODS Alloys". Advanced Materials Research 239-242 (maj 2011): 864–67. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.864.

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As high-temperature metallic materials, Co-base ODS alloys were produced by means of mechanical alloying, spark plasma sintering and hot rolling. Co-3wt%Al-1.2wt%Hf-ODS alloy was found to be an attractive composite like material, which is formed by spinodal like decomposition. The metastable phases were traced by hard phase containing dense oxide particles and soft one containing less oxide particles. Their tensile stress at 1,000 °C was improved by Hf addition that forms Y2Hf2O7type oxide particles and shortens their space distance.

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Lopez, H. F. "Alloy Developments in Biomedical Co-Base Alloys for HIP Implant Applications". Materials Science Forum 736 (grudzień 2012): 133–46. http://dx.doi.org/10.4028/www.scientific.net/msf.736.133.

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The development of cobalt alloys for the development of HIP implants has been evolving overtime. Accordingly, in this work an overview of the main microstructural factors that impact the mechanical properties, as well as the effect of interstitials such as carbon and nitrogen. In addition the role alloy pre-straining and heat treating on the amount of ε-martensite and on the exhibited mechanical properties is described. In general, it is shown that as the amount of ε-martensite exceeds 60 vol. percent, the alloy ductility is drastically reduced as the HCP phase becomes dominant in the matrix.

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Zhang, Lin, Xuanhui Qu, Xinbo He, Din Rafi-ud, Mingli Qin i Hongmin Zhu. "Hot deformation behavior of Co-base ODS alloys". Journal of Alloys and Compounds 512, nr 1 (styczeń 2012): 39–46. http://dx.doi.org/10.1016/j.jallcom.2011.08.097.

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Hu, Chun Lian, i Shang Lin Hou. "Study on Microstructure and Oxidation-Resistance of Superalloy Coating with Ni-Base Substituting for Co-Base". Advanced Materials Research 581-582 (październik 2012): 586–89. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.586.

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Microstructures, morphologies and energy spectrums of oxidized films and their cross sections of plasma sprayed alloy coating Co-02 with Co-base, Co-04 whose matrix is nickel partially instead of cobalt and NDCo-02 with Ni-base substituting for Co-base were investigated. The result indicates that the coatings of these three kinds of alloys are white austenite base and Cr7C3 and Cr7(C, B)3 eutectic; Co-02 produces Cr2O3 oxidation protection film, and there were distinct areas with shortage of chromium in Co-04 and NDCo-02 coatings where CoCr2O4 and NiCr2O4 oxidation protection films were produced with spinel structure, these efficiently improved oxidation resistance; these three kinds of alloys have super oxidation resistance which increases according to NDCo-02,Co-04 and Co-02 orderly. The level of oxidation resistance was assessed.

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Gu, Yue Feng, C. Cui, D. Ping, Hiroshi Harada, Akihiro Sato i J. Fujioka. "Development of New Generation Turbine Disk Superalloys in the HTM21 Project". Materials Science Forum 546-549 (maj 2007): 1277–80. http://dx.doi.org/10.4028/www.scientific.net/msf.546-549.1277.

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A new kind of cast & wrought (C&W) Ni-Co base superalloys named as “TMW alloys” was developed recently for compressor and turbine disk of gas turbine engines in the High Temperature Materials 21 Project at the National Institute for Materials Science (NIMS) in Japan. These Ni-Co base superalloys combine the characters of two kinds of γ- γ’ two-phase alloys (Ni-base and Co-base superalloys) and can be fabricated by cheap cast and wrought processing route. The results showed that some of these TMW alloys have superior tensile strength at temperatures up to 750 °C and higher creep resistances up to 725 °C than commercial UDIMET 720 LI alloy.

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Schenk, Th, D. Holland-Moritz, W. Bender i D. M. Herlach. "Statistical analysis of nucleation in undercooled Co-base alloys". Journal of Non-Crystalline Solids 250-252 (sierpień 1999): 694–98. http://dx.doi.org/10.1016/s0022-3093(99)00162-3.

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Mukherji, Debashis, i Joachim Rösler. "Design Considerations and Strengthening Mechanisms in Developing Co-Re-Based Alloys for Applications at + 100°C above Ni-Superalloys". Advanced Materials Research 278 (lipiec 2011): 539–44. http://dx.doi.org/10.4028/www.scientific.net/amr.278.539.

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Although Ni-base superalloys meet the gas turbine needs of today, they are used very close to their melting range. Demands for applications at higher temperatures are presently met partly through component cooling and application of thermal barrier coatings. However, this approach can not be sustained indefinitely unless the base metal melting temperature is also significantly increased. Rhenium addition can substantially increase the melting point in Co-base alloys and thereby provide a unique opportunity in the development of new alloys for very high temperatures – e.g. for applications at +100°C metal temperature above present day single crystal Ni-base superalloys. The design considerations behind the Co-Re alloy development are presented in this paper. Selected results from the alloy development studies are also presented.

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Rozprawy doktorskie na temat "Co-base alloys"

SILVA, SUELANNY C. da. "Estudo da influência da temperatura nas propriedades magnéticas e na microestrutura nos imãs permanentes à base de Pr-Fe-B-Nb-Co obtidos com hidrogênio". reponame:Repositório Institucional do IPEN, 2007. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11612.

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Made available in DSpace on 2014-10-09T12:53:51Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T13:58:57Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

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Silva, Suelanny Carvalho da. "Estudo da influência da temperatura nas propriedades magnéticas e na microestrutura nos ímãs permanentes à base de Pr-Fe-B-Nb-Co obtidos com hidrogênio". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-24102011-104115/.

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Pós magnéticos foram produzidos utilizando o processo de hidrogenação, desproporção, dessorção e recombinação (HDDR). A primeira parte deste trabalho envolveu o estudo do efeito da adição de Co na liga Pr14FebalCoxB6Nb0.1 (x= 0, 4, 8, 10, 12, 16) variando a de temperatura de dessorção/ recombinação de 800° a 900°C, com o objetivo de otimização do tratamento HDDR. A liga Pr14Fe80B6 foi utilizada como padrão. As ligas foram tratadas termicamente a 1100°C por 20 horas para eliminação do Fe- exixtente na liga em estado bruto de fusão. A temperatura de dessorção/ recombinação afetou a microestrutura e as propriedades magnéticas dos ímãs moldados com polímeros. A liga com baixa adição de cobalto (4 at.%) exigiu a temperatura de reação mais alta (880°C) entre os demais ímãs. As temperaturas ótimas para as ligas com 8 at.% Co e 10 at.% Co foram 840°C e 820°C, respectivamente. Ligas com altas concentrações de cobalto (12 at.% and 16 at.%) foram processadas a 840°C. A temperatura de dessorção/ recombinação que apresentou alta anisotropia nas ligas Pr14Fe80B6 e Pr14Fe79,9B6Nb0,1 foi de 820°C. O ímã que apresentou melhor remanência (862mT) foi processado com a liga Pr14Fe67,9Co12B6Nb0,1. Cada liga apresentou uma temperatura de reação otimizada e exibiu uma microestrutura particular, de acordo com a composição. A segunda parte deste trabalho envolveu a caracterização, dos pós HDDR de Pr14Fe80B6, que foram analisadas por difração de raios X com fonte síncrotron para a identificação e quantificação de fases cristalinas, e ainda para a determinação do tamanho médio de cristalitos da fase principal. A microscopia eletrônica de varredura (MEV) foi utilizada para revelar a morfologia dos pós HDDR.
Fine magnetic powders were produced using the hydrogenation disproportionation desorption and recombination (HDDR) process. The first stage in this work involved an investigation of the effect of the Co content and range of desorption/ recombination temperatures between 800 and 900°C with the purpose of optimizing the HDDR treatment for Pr14Fe80B6 and Pr14FebalCoxB6Nb0,1 (x= 0, 4, 8, 10, 12, 16) alloys. The cast alloys were annealed at 1100°C for 20 hours for homogenization. The processing temperature (desorption/ recombination) affected the microstructure and magnetic properties of the bonded magnets. The alloy with low cobalt content (4 at.%) required the highest reaction temperature (880°C) to yield anisotropic bonded magnets. The optimum temperature for alloys with 8 at.% Co and 10 at.% Co were 840°C and 820°C, respectively. Alloys with high cobalt content (12 at.% and 16 at.%) were processed at 840°C. The optimum desorption temperature for achieving high anisotropy for Pr14Fe80B6 and Pr14Fe79,9B6Nb0,1 was 820°C. The best remanence (862mT) was achieved with the Pr14Fe67,9B6Co12Nb0,1 magnet, processed at 840°C. Each alloy required an optimum reaction temperature and exhibited a particular microstructure according to the composition. The second stage of the work involved the characterization, for each temperature, of the Pr14Fe80B6 HDDR powder processed using X-ray diffraction analysis. The samples of the HDDR material were studied by synchrotron radiation powder diffraction using the Rietveld method for cell refinement, phase quantification and crystallite sizes determination. Scanning electron microscopy (SEM) has also been employed to reveal the morphology of the HDDR powder.

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Hunter, Elizabeth Adele Outdoor. "The smallest base and precious metal deposits in the world : vapor transport and deposition of bronze-Co-Ag alloys in vesicles /". Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1932.pdf.

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Hunter, Elizabeth Adele Outdoor. "The Smallest Base and Precious Metal Deposits in the World: Vapor Transport and deposition of Co-Cu-Sn-Ag alloys in vesicles". BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/1406.

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Metallic bronze-Co-Ag alloys ranging from1-90 µm have been discovered in bomb and lava vesicles from the mafic volcanoes of Kilauea in Hawaii and Vesuvius, Stromboli and Etna in Italy. It is inferred that the metals for these alloys were transported (in part) as chloride complexes, and that the metal ratios in the alloys may be a function of S/Cl. Alloy compositions in each system are extremely heterogeneous with Co concentrations from 1% to 94%, Cu from 2% to 89%, Sn from 1% to 22% and Ag from 0.5% to 42%. Maximum abundances (in wt%) of other trace or minor elements are, Fe (3.0), Zn (0.11), As (0.50), Pd (0.05), Pt (0.05), Au (0.05), Hg (0.10) and Pb (.13) Spot analyses and element maps of alloy grains reveal that three major exsolved components exist. They are bronze, Co, and Ag. Kilauean alloys are dominantly Cu-Sn (bronze) with little Co and Ag while a systematic decrease in the bronze component and an increase in Co occurs in grains from Stromboli to Etna to Vesuvius. Element maps show a covariance of Cu and Sn while Co and Ag concentrations vary independently. Element maps of the alloys also reveal that chlorides are occasionally present in the same vesicles as the alloys. Sulphur content of the metal alloys rarely exceed about 0.4 wt%. Electron back-scatter diffraction (EBSD) was employed for lattice characterization of the exsolved phases and shows a FCC structure for the Cu-Sn section of the alloys. Cu-Sn alloys high in Sn are successfully indexed using the Cu6Sn5 pattern (hexagonal), even though the Sn:Cu ratio of our alloys is considerably lower than 5:6. Cu-Sn alloys containing significant subequal amounts of Co and Fe (≈5 wt% each) indexes as body-centered cubic (BCC). The presence of alloys suggests metal transport as complexes in a vapor phase before being reduced to native metals. Our current model for the origin of the alloys suggests that the metals are transported to vesicles as chlorides and then deposited as sulfides and/or native metals. Oxidation and removal of most of the S then occurs. This data suggests that in some circumstances Cu-Sn-Co and Ag are readily partitioned into escaping magmatic volatiles during quenching of mafic magma. Further examination into vesicle-hosted alloys may confirm that the ratio of Cu, Ag, Au, Zn, and Pb in vesicles reflects the ratio of available metals present in the magma and in subsequent ore deposits.

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Wang, Jun. "Alliages base Cobalt en surfusion sous champ magnétique intense : propriétés magnétiques et comportement à la solidification". Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00870412.

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Ce travail est dédié à l'étude de l'effet des champs magnétiques sur les propriétés magnétiques et le comportement à la solidification d'alliages à base de Cobalt en surfusion sous champ magnétique intense. Les alliages à base Co sont d'excellents candidats pour obtenir une surfusion en dessous ou proche du point de Curie sous champ intense en raison du faible écart entre ce point de Curie et la température du liquidus. Dans cette étude, un dispositif haute température de surfusion intégrant une mesure magnétique a été construit dans un aimant supraconducteur, et est utilisé pour la mesure in situ de l'aimantation de liquides surfondus et pour l'étude du sur-refroidissement et de l'évolution de la microstructure de solidification en champ intense. Le cobalt liquide en surfusion est fortement magnétique sous champ, et son aimantation est même supérieure à celle du solide au chauffage à la même température. L'aimantation de l'alliage proche eutectique Co-B en surfusion dépend de la température de surchauffe, tandis que le Co-Sn en surfusion est toujours paramagnétique. La surfusion moyenne et l'étendue de la recalescence de différents métaux et alliages est affectée par un champ externe. En champ magnétique uniforme, la surfusion du Cuivre est amplifiée, tandis que la surfusion du Cobalt et de Co-Sn reste identique. Cependant, l'étendue de la recalescence du Cobalt et de Co-Sn est réduite, et l'effet est d'autant plus important pour des teneurs supérieures en Cobalt. Le champ magnétique promeut la précipitation de la phase dendritique a-Co et la formation d'eutectique anormal dans la microstructure des alliages Co-Sn surfondus. Les processus d'évolution de la microstructure sont affectés par le champ magnétique, et dépendent de l'intensité du champ et de la surfusion. Ce travail offre de nouveaux horizons dans l'étude des propriétés magnétiques d'alliages métalliques en forte surfusion et dans l'étude de la solidification hors équilibre sous champ magnétique intense.

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Dupin, Nathalie. "Contribution à l’évaluation thermodynamique des alliages polyconstitués à base de nickel". Grenoble INPG, 1995. http://www.theses.fr/1995INPG0040.

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La coexistence des phases gamma de structure cubique a faces centrees a1 et gamma' de structure cubique a faces centrees l1#2 confere aux superalliages base nickel leurs exceptionnelles proprietes mecaniques a hautes temperatures. Des calculs thermodynamiques bases sur l'evaluation des systemes simples constitutifs de ces alliages complexes, contenant au moins huit elements, peuvent permettre de reduire le nombre d'experimentations a entreprendre pour optimiser leur compositions et les traitements thermiques associes. Dans ce but, ce travail presente l'etude thermodynamique des phases constituant les systemes quaternaires al-cr-ni-ta et al-cr-ni-ti. La premiere partie presente les modeles adaptes a la description du comportement thermodynamique des phases intermetalliques etudiees. La presentation du modele en sous-reseaux est particulierement detaillee. Les contraintes necessaires a la description des phases a1 et l1#2 par une meme expression mathematique sont derivees a partir de l'identification des modeles a deux et quatre sous-reseaux de la phase l1#2. Les chapitres suivants analysent les systemes binaires al-co, al-ni, cr-ta et ternaires al-co-ni, al-cr-ni, al-ni-ti, al-ni-ta, cr-ni-ta et cr-ni-ti. Les parametres thermodynamiques decrivant les phases constituant ces systemes sont obtenus dans un processus d'optimisation prenant en compte l'ensemble des donnees experimentales, souvent rares, publiees sur ces systemes. L'extension des parametres thermodynamiques ainsi determines aux systemes quaternaires al-cr-ni-ta et al-cr-ni-ti sans optimisation supplementaire justifie la demarche entreprise. Une base thermodynamique permettant le calcul des equilibres de phases dans les superalliages base nickel a donc ainsi ete constituee

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Naujoks, Dennis [Verfasser], Alfred [Gutachter] Ludwig i Gunther [Gutachter] Eggeler. "Application of combinatorial materials science methods to model alloys for the understanding of phase stabilities, oxidation behavior and atomic mobility in Ni- and Co-base superalloys / Dennis Naujoks ; Gutachter: Alfred Ludwig, Gunther Eggeler ; Fakultät für Maschinenbau". Bochum : Ruhr-Universität Bochum, 2019. http://d-nb.info/1212664078/34.

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Ben, Mbarek Wael. "Synthèse, caractérisation et application des alliages à base de Mn-X-Y (X=Al; Y=Fe,Co) et Ca-Al dans la dégradation d'un colorant azoïque "Black 5" utilisé dans l'industrie de textile". Doctoral thesis, Universitat de Girona, 2018. http://hdl.handle.net/10803/666563.

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This work is framed in the general context of the synthesis and characterization of Mn or Ca based alloys, which are subsequently applied in degradation processes of azo dyes used in the textile industries. The alloys were produced by three techniques: arc melting (bulk), rapid solidification (ribbon) and ball milling (powder). The low value of the activation energy and the fast kinetics of degradation makes the alloys of the Mn-Al system candidates for use in the treatment of decolorization of wastewater. Fe or Co addition has been aanalyzed. The low resistance to corrosion of Fe increases the rate of the degradation reaction. On the other hand, the results obtained in the Ca-Al system show that are effective reducing azo dyes under neutral pH conditions
Aquest treball s'enmarca en el context general de la síntesi i caracterització d'aliatges de base Mn o Ca que són utilitzats en processos de degradació de colorants azo habitualment emprats en les indústries tèxtils. Els aliatges han estat produïts essencialment per tres tècniques: fusió per arc (arc melting), refredament ràpid en una roda giratòria (melt spinning) per a la producció de cintes i mòlta mecànica (ball milling) per a la producció de pols. El baix valor de l'energia d'activació i la ràpida cinètica de degradació fa que els aliatges del sistema Mn-Al siguin candidats a ser utilitzats en el tractament de decoloració d'aïgues residuals industrials. S'ha analitzat l'addició de Fe o Co. La baixa resistència a la corrosió del Fe augmenta la velocitat de la reacció de degradació. Per altra banda, els resultats obtinguts en el sistema Ca-Al mostren que són agents reductors efectius en condicions de pH neutre

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Vermeulen, Jean-Luc. "Elaboration par pulvérisation ionique et caractérisation de couches minces ferromagnétiques à forte perméabilité". Grenoble 1, 1993. http://www.theses.fr/1993GRE10071.

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Dans le cadre des applications employant des materiaux ferromagnetiques aux hyperfrequences, nous avons etudie les proprietes magnetiques et electriques de couches minces ferromagnetiques metalliques et dielectriques deposees par pulverisation ionique. Le premier volet de ce memoire se rapporte a l'installation de depot. Des parametres cles tels que l'orientation de la cible et la temperature du substrat font l'objet d'une analyse approfondie. Cette etude a permis ainsi d'aboutir a l'obtention de couches denses de qualite maitrisee. Sur la base de ces preliminaires, des films minces microcristallises de co-fe-si-b ont ete elabores et caracterises. L'analyse des proprietes magnetiques statiques et dynamiques en fonction des conditions experimentales montre qu'elles sont particulierement sensibles aux deux parametres: temperature de depot et bombardement ionique. Leur controle a permis ainsi de realiser des couches presentant a la fois des permeabilites elevees a basse frequence et de fortes pertes a des frequences plus hautes. En dernier lieu, l'accent est mis sur la realisation et l'etude de couches resistives de b-n et de fe-b-n. Nous montrons qu'il est possible d'obtenir, grace a un bombardement simultane d'ions azote de la couche en croissance, des depots nitrures de concentration en azote variable dans l'intervalle 0-50 pour cent. Concernant les depots de fe-b-n, une forte dependance des caracteristiques electromagnetiques vis-a-vis de la composition a ete observee. Selon la concentration de fer, les proprietes du compose evoluent d'un caractere fortement ferromagnetique et conducteur, a un comportement tres resistif mais a faible induction a saturation

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Abdul-Latif, Akrum. "Approches multi-échelles pour la description de l'anélasticité avec endommagement". Compiègne, 1994. http://www.theses.fr/1994COMP678S.

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Ce mémoire comporte deux parties. Partie 1 : DESCRIPTION MACROSCOPIQUE DU COMPORTEMENT ANELASTIQUE. Le comportement plastique du Waspaloy manifeste un surécrouissage portant sur les deux composantes isotropes et cinématique qu'on se propose de modéliser. Pour cela on utilise un modèle de plasticité de l'ONERA-LMT, que l'on modifie afin de rendre compte du surécrouissage dû aux trajets de chargement non-proportionnels. Après confrontation entre les résultats prévisionnels du modèle et les résultats expérimentaux, il s'avère que la modélisation proposée rend bien compte d'une façon satisfaisante du comportement de cet alliage. Partie 2 : MODELISATION MICROMECANIQUE DU COMPORTEMENT ENDOMMAGEABLE. En se basant sur l'approche micromécanique de comportement anélastique non-endommageable des polycristaux, nous proposons dans cette partie un modèle micromécanique du comportement anélastique endommageable en fatigue plastique oligocyclique. Une variable endommagement scalaire ds est introduite au niveau de chaque système de glissement SG de cristaux CFC. Cette variable représente la naissance et la croissance de micro-rupture sur chaque SG localisé en surface libre. Le couplage entre le comportement et l'endommagement aux différents niveaux est soigneusement discuté. Des simulations numériques sous chargements simples et complexes en fatigue plastique sont réalisées. Ceci permet de montrer les capacités prédictives du modèle.

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Książki na temat "Co-base alloys"

United States. National Aeronautics and Space Administration., red. 10,000-hour cyclic oxidation behavior at 982 C (1800 F) of 68 high-temperature Co, Fe-, and Ni-base alloys. [Washington, D.C: National Aeronautics and Space Administration, 1997.

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A, Barrett Charles, i United States. National Aeronautics and Space Administration., red. The effect of Cr, Co, Al, Mo, and Ta on a series of cast Ni-base superalloys on the stability of an aluminide coating during cyclic oxidation in Mach 0.3 burner rig. [Washington, D.C.]: National Aeronautics and Space Administration, 1986.

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10,000-hour cyclic oxidation behavior at 982 C (1800 F) of 68 high-temperature Co, Fe-, and Ni-base alloys. [Washington, D.C: National Aeronautics and Space Administration, 1997.

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Advanced thermal barrier system bond coatings for use on Ni, Co-, and Fe-base alloy substrates. [Cleveland, Ohio: National Aeronautics and Space Administration, Lewis Research Center, 1985.

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Części książek na temat "Co-base alloys"

Chen, G. L., L. Z. Zhuang i J. L. Xu. "Effects of Cobalt on the Microstructures and Mechanical Properties of the Fe-Ni-Co-Base Superalloy Refractoloy26". W High Temperature Alloys, 317–26. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-1347-9_30.

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Wertz, Katelun, Donald Weaver, Dongsheng Wen, Michael S. Titus, Rajiv Shivpuri, Stephen R. Niezgoda, Michael J. Mills i S. Lee Semiatin. "Supersolvus Hot Workability and Dynamic Recrystallization in Wrought Co–Al–W-Base Alloys". W Superalloys 2020, 857–69. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-51834-9_84.

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Kimura, Yoshisato, Kiichi Sakai, Shinya Teramoto i Yoshinao Mishima. "Microstructure Control of Co₃AlC-Base Heat Resistant Alloys Using Optical Floating Zone Melting". W Materials Science Forum, 833–36. Stafa: Trans Tech Publications Ltd., 2005. http://dx.doi.org/10.4028/0-87849-960-1.833.

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Black, Jonathan. "In vivo Corrosion of a Cobalt-Base Alloy and Its Biological Consequences". W Biocompatibility of Co-Cr-Ni Alloys, 83–100. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4613-0757-0_8.

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Makineni, Surendra K., Abhishek Sharma, Prafull Pandey i Kamanio Chattopadhyay. "An Overview on Co-Base Alloys for High Temperature Applications". W Reference Module in Materials Science and Materials Engineering. Elsevier, 2020. http://dx.doi.org/10.1016/b978-0-12-803581-8.12094-6.

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Nartu, Mohan Sai Kiran Kumar Yadav, Shashank Sharma, Srinivas Aditya Mantri, Sameehan S. Joshi, Mangesh V. Pantawane, Sangram Mazumder, Narendra B. Dahotre i Rajarshi Banerjee. "Directed-Energy Deposition". W Additive Manufacturing in Biomedical Applications, 130–59. ASM International, 2022. http://dx.doi.org/10.31399/asm.hb.v23a.a0006885.

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Abstract This article focuses on the directed-energy deposition (DED) additive manufacturing (AM) technique of biomedical alloys. First, it provides an overview of the DED process. This is followed by a section describing the design and development of the multiphysics computational modeling of the layer-by-layer fusion-based DED process. A brief overview of the primary governing equations, boundary conditions, and numerical methods prescribed for modeling laser-based metal AM is then presented. Next, the article discusses fundamental concepts related to laser surface melting and laser-assisted bioceramic coatings/composites on implant surfaces, with particular examples related to biomedical magnesium and titanium alloys. It then provides a review of the processes involved in DED of biomedical stainless steels, Co-Cr-Mo alloys, and biomedical titanium alloys. Further, the article covers novel applications of DED for titanium-base biomedical implants. It concludes with a section on the forecast of DED in biomedical applications.

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Wu, Kaidi, i Thomas Talhelm. "Hide a Dagger Behind a Smile". W The Oxford Handbook of the Psychology of Competition, C26P1—C26N1. Oxford University Press, 2023. http://dx.doi.org/10.1093/oxfordhb/9780190060800.013.26.

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Abstract In this chapter, we review cultural differences in people’s attitudes about competition, why cultures differ in competition, and how they compete in different ways. Researchers have long associated collectivistic culture with harmony and cooperation. However, the bulk of the evidence suggests that collectivistic cultures compete more, and more intensely, than individualistic cultures. Collectivists are more likely to see competition as zero-sum, engage in social comparison, and base their self-worth on common standards rather than self-defined goals. This raises a paradox: where does the popular conception of harmony in collectivism come from? In reviewing prior studies, we find that people in collectivistic cultures tend to use indirect, hidden methods to compete against others. This allows for an outward harmony, without negating competition. We ask whether competition in collectivistic cultures is only stronger when competing with outsiders. Studies reject this speculation. Rather, people in collectivistic cultures compete more with in-group members and are more vigilant toward classmates and co-workers. Next, we explore how people from different cultures decide to enter into competition. We find that collectivists’ tendency to enter into prestigious competitive environments might end up harming them. Finally, we discuss whether there can be versions of collectivistic groups without competition or whether this is a utopian dream.

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SivachandarK., V. Amudha, B. Ramesh, Jose Anand, M. ShanmugaSundari i Jerril Gilda S. "MIMO-IDMA System Performance for SUI and LTE Frequency Selective Channels". W Advances in Parallel Computing Algorithms, Tools and Paradigms. IOS Press, 2022. http://dx.doi.org/10.3233/apc220059.

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The spectrum used by Code Division Multiple Access (CDMA) allows for a signal with a greater bandwidth by spreading electromagnetic energy. Multi-Carrier CDMA (MC-CDMA) is a telecommunications numerousentrée strategy that spreads each user symbol across the frequency domain with distinct codes. Cognitive Radio (CR) is a vibrant spectrum admittance enabling technology by dynamically allocating space for fundamental users by modifying its settings and base station. Two models for people on the cognitive spectrum are Opportunistic Spectrum Access (OSA) and Concurrent Spectrum Access (CSA). Using Co-Channel Interference (CCI) and Adjacent Channel Interference (ACI), the MC-CDMA system is an effective accessing strategy for multi-user data transmission (ACI). Multiple-Input Multiple-Output (MIMO) involving Space-Time Transmit Diversity (STTD), Spatial Multiplexing (SM), and collaborative MIMO is used for numerous data communication, and dependable Bit Error Rate (BER) presentation is attained. STBC (Space Time Block Coding) is equipped with two antennas and codes for data transmission across multiple antennas. At the receiver, STBC offers channel state information while maintaining a low level of complexity. The image’s pixels will be shuffled using Arnold’s Cat Map (ACM) encryption method. When compared to other compression methods, Integer Wavelet Transform (IWT) compression is stress-free. The Internet of Things (IoT) is used to examine tracklatency and power stages, STTD MC-CDMA faultoutput utilizing cognitive spectrum, and channel simulated parameterization. The output on fault levels with patient caring using Stanford University Interim (SUI) and Long Term Evolution (LTE) techniques with a Double STTD (DSTTD) assisted MC-CDMA cognitive spectrum system.

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Taber, Douglass F. "Functional Group Protection: The Pohl Synthesis of β-1,4-Mannuronate Oligomers". W Organic Synthesis. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190646165.003.0015.

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D. Srinivasa Reddy of the National Chemical Laboratory converted (Org. Lett. 2015, 17, 2090) the selenide 1 to the alkene 2 under ozonolysis conditions. Takamitsu Hosoya of the Tokyo Medical and Dental University found (Chem. Commun. 2015, 51, 8745) that even highly strained alkynes such as 4 can be generated from a sulfinyl vinyl triflate 3. An alkyne can be protected as the dicobalt hexacarbonyl complex. Joe B. Gilroy and Mark S. Workentin of the University of Western Ontario found (Chem. Commun. 2015, 51, 6647) that following click chemistry on a non-protected distal alkyne, deprotection of 5 to 6 could be effected by exposure to TMNO. Stefan Bräse of the Karlsruhe Institute of Technology and Irina A. Balova of Saint Petersburg State University showed (J. Org. Chem. 2015, 80, 5546) that the bend of the Co complex of 7 enabled ring-closing metathesis, leading after deprotection to 8. Morten Meldal of the University of Copenhagen devised (Eur. J. Org. Chem. 2015, 1433) 9, the base-labile protected form of the aldehyde 10. Nicholas Gathergood of Dublin City University and Stephen J. Connon of the University of Dublin developed (Eur. J. Org. Chem. 2015, 188) an imidazolium catalyst for the exchange deprotection of 11 to 13, with the inexpensive aldehyde 12 as the acceptor. Peter J. Lindsay-Scott of Eli Lilly demonstrated (Org. Lett. 2015, 17, 476) that on exposure to KF, the isoxazole 14 unraveled to the nitrile 15. Masato Kitamura of Nagoya University observed (Tetrahedron 2015, 71, 6559) that the allyl ester of 16 could be removed to give 17, with the other alkene not affected. Benzyl ethers are among the most common of alcohol protecting groups. Yongxiang Liu and Maosheng Cheng of Shenyang Pharmaceutical University showed (Adv. Synth. Catal. 2015, 357, 1029) that 18 could be converted to 19 simply by exposure to benzyl alcohol in the presence of a gold catalyst. Reko Leino of Åbo Akademi University developed (Synthesis 2015, 47, 1749) an iron catalyst for the reductive benzylation of 20 to 21. Related results (not illustrated) were reported (Org. Lett. 2015, 17, 1778) by Chae S. Yi of Marquette University.

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i Martinez, Agustí Cerrill. "Accessing Administration's Information via Internet in Spain". W Global Information Technologies, 2558–73. IGI Global, 2008. http://dx.doi.org/10.4018/978-1-59904-939-7.ch186.

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Information in the hands of public administrations plays a fundamental role in developing democracies and carrying out daily tasks—not only the public administrations’ tasks, but also those of the general public and companies (European Commission, 1998). New information and communications technologies (ICT) are vastly increasing the range of information in the hands of the general public and considerably diversifying both quantitatively and, above all, qualitatively the tools for conveying this, with the Internet being the means chosen by Organisation for Economic Co-Operation and Development (OECD) Member States to provide the general public with access to the information held by the administration (OECD, 2003). Nowadays, public administrations create, collect, develop and disseminate large amounts of information: business and economic information, environmental information, agricultural information, social information, legal information, scientific information, political information and social information. Access to information is the first step towards developing e-governments and is something that has grown most in recent years, not only from the viewpoint of supply but also of demand. At present, most people using e-government do so to obtain information from public administrations. Throughout history, information has not always had the same relevance or legal acknowledgement in the West. Bureaucratic public administrations had no need to listen to the general public nor notify citizens of their actions. Hence, one of the bureaucratic administration’s features was withholding the secret that it had legitimized, since this was considered the way to maintain the traditional system of privileges within the bureaucratic institution—by making control and responsibility for information difficult, and also by allowing the public administration to free itself of exogenous obstacles (Arteche, 1984; Gentot, 1994). In most European countries, except the Nordic countries (Sweden, Norway, Finland), secrets were the dominant principle. For instance, it was not until 1978 that France passed a law concerning access to public sector information; in 1990, Italy did likewise. Crises in the bureaucratic model of public administration have brought with them the existence of new models. Receptivity, focusing on the client and quality management, have been some responses to the crisis of this model in the 1980s and 1990s, since the advent of the post-bureaucratic paradigm ( Mendieta, 1996; Behn, 1995). The process of modernizing Public administrations has meant that those governed have come to be considered clients of these administrative services (Brugué, Amorós, & Gomà, 1994). Citizens, considered as clients, now enjoy a revitalized status as seen from public administrations, which provides citizens with a wide range of rights and powers in order to carry out their needs, including obtaining information from the administration (Chevalier, 1988). This process has coincided over the years with the rules regulating access to public-sector information being extended in countries of the West. But the evolution does not stop here. Societies that are pluralist, complex and interdependent require new models of public administration that allow the possibility of responding and solving present challenges and risks (Kooiman, 1993; OECD, 2001b). Internet administration represents a model of public administration based on collaboration between the administration and the general public. It has brought about a model of administration that was once hierarchical to become one based on a network in which many links have been built between the different nodes or main active participants, all of whom represent interests that must be included in the scope of general interest due to the interdependence existing between them (Arena, 1996). The way the administration is governed online requires, first and foremost, information to be transparent, with the aim of guaranteeing and facilitating the participation of all those involved (European Commission, 2001). It is essential that all those involved in the online process are able to participate with as much information as possible available. Information is an indispensable resource for decision-making processes. The strategic participants taking part in these will consider the information as an element upon which they may base their participation online. Information becomes a resource of power that each participant may establish, based on other resources he or she has available, and this will influence their strategies in the Internet. This allows us to see that the networks distributing information may be asymmetrical, which leads to proposing a need to adopt a means to confront this asymmetrical information. In this task, ICT can be of great help with the necessary intervention of law. Public-sector information has an important role in relation with citizens’ rights and business. Public administration also needs information to achieve its goals.

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Streszczenia konferencji na temat "Co-base alloys"

Gu, Y. F., C. Cui, H. Harada, T. Fukuda, D. Ping, A. Mitsuhashi, K. Kato, T. Kobayashi i J. Fujioka. "Development of Ni-Co-Base Alloys for High-Temperature Disk Applications". W Superalloys. TMS, 2008. http://dx.doi.org/10.7449/2008/superalloys_2008_53_61.

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Galun, R., Andreas Weisheit i Barry L. Mordike. "Surface alloying of magnesium base alloys with high-power CO 2 -laser". W XI International Symposium on Gas Flow and Chemical Lasers and High Power Laser Conference. SPIE, 1997. http://dx.doi.org/10.1117/12.270179.

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Fahrmann, Michael G., Vinay P. Deodeshmukh i S. Krishna Srivastava. "HAYNES NS-163 Alloy: A Novel Nitride Dispersion-Strengthened Co-Base Alloy". W ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-25452.

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HAYNES® NS-163® alloy was developed by Haynes International Inc. for high-temperature structural applications with a dual manufacturing approach in mind: the fabrication of components in the readily weldable and formable mill-annealed condition, and their subsequent strengthening by means of a gas nitriding process. The alloy was designed to be conducive to dispersion strengthening by virtue of the formation of internal Ti- and Nb-rich nitrides. Since this process is diffusion-controlled, component section thicknesses are presently limited to approximately 2.0 mm (0.080″). The paper presents key parameters of the devised commercial nitridation process and the resulting microstructures and mechanical properties of sheet samples, which originated from a production-scale heat. Oxidation resistance and the need for coatings at temperatures exceeding 980°C (1800°F) are addressed as well. It is shown that this new alloy has the potential to fill the gap between today’s strongest solid-solution strengthened alloys and the oxide-dispersion strengthened mechanically alloyed materials.

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Schoonbaert, Stephen, Xiao Huang, Scott Yandt i Peter Au. "Brazing and Wide Gap Repair of X-40 Using Ni-Base Alloys". W ASME Turbo Expo 2007: Power for Land, Sea, and Air. ASMEDC, 2007. http://dx.doi.org/10.1115/gt2007-27340.

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Co-base superalloys are commonly used for vanes and parts of the combustion chamber in gas turbine engines. The Co-base superalloys are primarily solid solution strengthened and have good resistance to hot corrosion, creep and thermal fatigue. In particular, Co-base alloy X-40 was used to fabricate the first stage NGV airfoils of T56 series engines; inspections after service have revealed that X-40 airfoils suffered from severe thermal fatigue damages. In this study, a new braze repair scheme is proposed; in which Ni-base alloys are used to repair the X-40 substrate in both narrow and wide gap configurations. Metallographic examination, X-ray mapping and EDS semi-quantitative compositional analyses were carried out to study the microstructures in the braze joint in the asbrazed condition and after thermal exposure at 950°C. The results obtained so far suggest the formation of Cr-rich borides, eutectic phases and various carbides in the joint. No TCP phases were found in the brazed joint and base metals adjacent to the joint. The high carbon content in the alloy X-40 may have played an important role in preventing the formation of TCP phases during brazing and subsequent thermal exposure.

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Werry, A., C. Chazelas, A. Denoirjean, S. Valette, A. Vardelle i E. Meillot. "Multi-Scale Structured Composite Coatings by Plasma Transferred Arc for Nuclear Applications". W ITSC2015, redaktorzy A. Agarwal, G. Bolelli, A. Concustell, Y. C. Lau, A. McDonald, F. L. Toma, E. Turunen i C. A. Widener. ASM International, 2015. http://dx.doi.org/10.31399/asm.cp.itsc2015p1086.

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Abstract In nuclear plants, the replacement of hardfacing Stellite, a cobalt-base alloy, on parts of the piping system in connection with the reactor has been investigated since the late 60’s. Various Fe-base or Ni-base alloys, Co-free or with a low content of Co, have been developed but their mechanical properties are generally lower than that of Stellites. The 4th generation nuclear plants impose additional or more stringent requirements for hardfacing materials. Plasma transferred arc (PTA) coatings of cobalt-free nickel-base alloys with the addition of sub-micrometric or micrometric alumina particles are thought to be a potential solution for tribological applications in the primary system of sodium-cooled fast reactors. In this study, PTA coatings of nickel-base alloys reinforced with alumina particles were deposited on 316L stainless steel substrates. The examination of coatings revealed a refinement of the microstructure. Under the conditions of the study, the addition of alumina particles did not improve the micro-hardness of coatings but improve their resistance to abrasive wear.

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Govender, Preyin, Deborah Clare Blaine i Natasha Sacks. "Influence Of Base Plate Coating On LPBF Of WC-Co". W World Powder Metallurgy 2022 Congress & Exhibition. EPMA, 2022. http://dx.doi.org/10.59499/wp225371527.

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While additive manufacturing (AM) is rapidly gaining ground as an established manufacturing process for many industries, understanding and controlling process parameters in order to develop validated process chains remains an area for research and development. A critical parameter that is relevant to laser powder bed fusion (LPBF), the most widely used metal AM technology, is baseplate material selection. This is especially relevant for uncommon build materials such as cemented carbides. In this study, LPBF of WC-Co cemented carbides is investigated, evaluating the influence of baseplate coating on the build. A DIN 1.2343 tool steel baseplate was used for WC-Co LPBF builds, both in the uncoated and coated state. WC-CoCr (1350VM) powder was used to coat the baseplate, while two WC-Co powders with different Co content (17 and 12 wt%, respectively) were used to compare builds of these alloys. The WC-Co powders were characterized to establish their suitability for LPBF. Cuboids were printed, with and without supports, on the coated and uncoated baseplates. Low density builds were built (~88% dense) relating to poor printing parameters. Evaporation of Co is present, yet WC-17Co samples on supports showed little evaporation and good build volume.

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Pint, Bruce A. "Simulated Fireside Corrosion of Ni-Base Alloys in Oxy-Fired Conditions at 700°–800°C". W ASME 2014 Symposium on Elevated Temperature Application of Materials for Fossil, Nuclear, and Petrochemical Industries. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/etam2014-1023.

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One future objective for coal-fired power generation is to develop advanced ultrasupercritical (A-USC) boilers that incorporate oxy-firing to facilitate carbon capture. The steam condition goals of 760°C/34.5 MPa will require major materials changes throughout the boiler, including Ni-base alloys in the hottest sections. Solution hardened alloys such as 740 and 282 are needed to meet the strength requirements for 760°C. In previous work, little difference in corrosion rate was found between air- and oxy-firing for alloy 740 at 600°–800°C so laboratory testing focused on the “worst case” oxy-firing conditions with higher CO2, H2O and SO2 than expected with air-firing. Model alloys were made to investigate the roles of Cr, Al, Ti, Co and Mo on the fireside corrosion behavior. Exposures conducted for 500h at 700° and 800°C found that Al and Ti additions typically reduced the extent of attack under these conditions. As expected, the alloy Cr content had a substantial effect between 18 and 22%. Additions of 4% and 8%Mo to Ni-20Cr-(0-20)Co alloys increased the metal loss at 800°C and Ni-20Cr-20Co-(0-8%)Mo showed the highest attack at 700°C. The much higher attack of alloy 282 at 800°C can likely be attributed to its lower Cr content compared to alloy 740, which was developed to have excellent fireside corrosion resistance. Paper published with permission.

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Mazars, P., D. Manesse i C. Lopvet. "Degradation of MCrA1Y Coatings by Interdiffusion". W ASME 1987 International Gas Turbine Conference and Exhibition. American Society of Mechanical Engineers, 1987. http://dx.doi.org/10.1115/87-gt-58.

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Coatings such as NiCrA1Y, CoCrA1Y and FeCrA1Y are deposited by plasma spraying under partial pressure on commercial f.c.c. alloys of nickel, cobalt, and iron. The interdiffusion between coating and substrate is limited in the cases of NiCrA1Y/Ni base and CoCrA1Y/Co base. On the other hand, rapid diffusion of the aluminium into the substrate occurs in the system FeCrA1Y/Fe base. When mixed systems MCrA1Y/M’ base are studied, an interdiffusion is usually observed between the elements M and M’ except in the case of the systems NiCrA1Y/Co base and FeCrA1Y/Co base where carbide diffusion barriers are formed.

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Huang, Xiao. "Microstructure and Oxidation Behaviour of NGB and WGB Joints With Boron/Silicon Free Nickel Base Braze Alloys". W ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-14017.

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Abstract In this study, the microstructure and solidus and liquidus of several Ni-Co-Hf-Zr-Ti-Al braze alloys were first examined with the objective to develop a B and Si free low melting braze alloy for narrow gap (NGB) and wide gap brazing (WGB) and turbine component repair applications. Among various alloys examined, DSC was used to measure the solidus and liquidus during heating and cooling cycles. Following the measurements of liquidus and solidus, the microstructure was evaluated using SEM. Equations for calculating solidus and liquidus based on alloy’s compositions were established and the functions of each elements on these two characteristic temperatures were discussed. One selected alloy with a liquidus of 1201 °C was further employed for NGB and WGB experiments. The results showed that it was able join CMSX-4 at 1240°C without interfacial voids; and with the use of externally applied pressure and extended homogenization treatment the interfacial intermetallic compounds were substantially removed. Furthermore, the same braze alloy was used to fill a large artificial cavity in a WGB scheme at a reduced temperature of 1200°C. The braze alloy was able to fully bond the filler powder alloy in addition to join the two alloys to a IN 738 substrate. Finally, oxidation test was conducted at 1050°C (isothermal in static air) for 100 hours after NGB of CMSX-4 and WGB of IN 738. The results showed that the oxide formed on the standalone braze alloy is very dense and there is no sign of spallation. It contained primarily NiO (+CoO) with no other elements measured. For the NGB joints, large amount of scale spallation was observed on base alloy CMSX-4 while the NGB joint remained spallation free. The oxide formed on the NGB was NiO with partitions of Co, Al, Ti, Cr, and W. The WGB joint region in IN 738 showed oxide scale spallation on the IN 738 substrate side, leaving behind steps and depression on the sample surface. In the WGB joint itself, there were three notable phases after oxidation test, however, no scale spallation could be found. For the majority part of the surface, a Ni-rich oxide covered the surface. There were areas of smaller oxide particles with higher Cr content. Overall, the new boron/silicon free braze alloy was found to be able to join several superalloys in both WGB and NGB schemes without occurrence of defects and the oxidation resistance was superior to both substrate alloys examined in this study.

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Hasselqvist, Magnus. "TMF Crack Initiation Lifing of Austenitic Carbide Precipitating Alloys". W ASME Turbo Expo 2004: Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-54333.

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Recent work within DDIT has shown that Ni base superalloys like HAYNES230, Co base superalloys like HAYNES188, super stainless steels like HAYNES HR-120, and stainless steels like 253MA are similar from a materials modelling point of view. They are austenitic, delivered solutioned, and precipitate secondary carbides and other brittle phases in service and during cyclic tests at elevated temperature. These new phases result in a significantly reduced RT ductility, while the high temperature ductility is at most moderately reduced. Therefore, TMF cycles, which repeatedly go down to low temperatures, see an embrittled alloy whereas LCF tests at Tmax (in the TMF cycle) do not. This suggests that the classical use of LCF data at Tmax might given non-conservative life estimates. Literature studies and materials testing have confirmed that TMF data may be well below LCF data at Tmax verifying the non-conservatism of the classical methodology. Furthermore, the cyclic life tends to decrease with decreasing Tmin in TMF tests, and IP TMF is usually more detrimental than OP TMF due to creep-fatigue interaction. While standard TMF tests are closer to reality than LCF tests, we are still not certain that they capture all detrimental effects under component cycling, and are running additional, carefully planned, TMF tests on aged specimen at low Tmin values to improve the analysis. More tests, especially biaxial IP TMF tests, will eventually be needed to get a comprehensive picture. A new TMF data backed model has, however, already shown a higher precision when compared with service experience than the classical creep-fatigue methodology which is calibrated with LCF data at Tmax. Further testing and analysis will enable us to refine the TMF model and extend it to additional ACP alloys. The main input to the TMF model is the stabilised inelastic strain range, as calculated by the constitutive model described in an earlier ASME Turbo paper, GT2002-30659.

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Raporty organizacyjne na temat "Co-base alloys"

Tomova, Zlatina, Angelina Vlahova, Christo Kissov, Rada Kazakova i Dimitar D. Radev. Corrosion Resistance and Biocompatibility of Multicomponent Ni- and Co ‑ Base Dental Alloys Obtained by Methods of Powder Metallurgy. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, lipiec 2018. http://dx.doi.org/10.7546/crabs.2018.07.05.

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Reynolds, Christian, Libby Oakden, Sarah West, Rachel Pateman i Chris Elliott. Citizen Science and Food: A Review. Food Standards Agency, marzec 2021. http://dx.doi.org/10.46756/sci.fsa.nao903.

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Citizen science and food is part of a new programme of work to explore how we can involve the communities we serve when building the evidence-base on which policy decisions are made. Citizen science is an approach that can provide high volumes of data with a wide geographic spread. It is relatively quick to deploy and allows access to evidence we would ordinarily have difficulty collating. This methodology has been endorsed by the European Commission for Research, Science and Innovation. There is no one size fits all definition, but citizen science projects involves engaging with communities and asking them to be part of the project, either through engaging them in data collection or through other ways of co-creation. For participants, citizen science offers learning opportunities, the satisfaction of contributing to scientific evidence and the potential to influence policy. It can also give us data which is high in volume, has wide geographical spread, is relatively quick to deploy and that we couldn’t access any other way. Projects using these methods often involve engaging with communities and asking them to be part of the project. This can be either through working with them in data collection, or through co-creation. This report demonstrates that the research community are already undertaking numerous pieces of research that align with FSA’s evidence needs. This includes examples from the UK and other global communities. Participants in such research have collected data on topics ranging from food preparation in the home to levels of chemical contaminant in foods. The findings of this report outline that citizen science could allow the FSA to target and facilitate more systematic engagement with UK and global research communities, to help address key research priorities of the FSA.

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