Дисертації з теми "Bulk alloys"
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Engman, Alexander. "Mechanical properties of bulk alloys and cemented carbides." Thesis, KTH, Materialvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-230897.
Повний текст джерелаAnv¨andandet av kobolt (Co) som bindefas-material i h°ardmetall har blivit ifr°agasatt som en f¨oljdav av de potentiella h¨alsoriskerna associerade med inhalering av koboltpartiklar. Kobolt anv¨ands p°agrund av dess utm¨arkta vidh¨aftande och v¨atande egenskaper, kombinerat med tillr¨ackliga mekaniskaegenskaper. Syftet med detta arbete ¨ar att unders¨oka de mekaniska egenskaperna hos Fe-Ni bulklegeringarochWC-Co h°ardmetall genom att anv¨anda Integrated Computational Materials Engineering(ICME) metoder kombinerat med FEM-data. Rapporten unders¨oker de mekaniska egenskapernahos flera bulklegeringar i Fe-Ni systemet. FEM-indentering och FEM-fraktur data interpoleras ochanv¨ands f¨or att modellera h°ardheten H och brottsegheten KIc. En modell f¨or utskiljningsh¨ardningbaserad p°a Ashby-Orowans ekvation implementeras f¨or att f¨oruts¨aga e↵ekten p°a brottgr¨ansen av utskiljdapartiklar. ¨Aven en modell f¨or l¨osningsh¨ardning implementeras. Existerande modeller anv¨andsf¨or att simulera egenskaperna hos WC-Co h°ardmetall tillsammans med modellen f¨or l¨osningsh¨ardning.Resultaten visar att de simulerade egenskaperna hos Fe-Ni bulklegeringar ¨ar j¨amf¨orbara medde f¨or kobolt. Dock kan de inte bekr¨aftas p°a grund av avsaknad av experimentell data. Egenskapernahos WC-Co h°ardmetall st¨ammer rimligt ¨overens med existerande experimentell data, meden genomsnittlig avvikelse av h°ardheten med 11.5% och av brottsegheten med 24.8%. Slutsatserna¨ar att det beh¨ovs experimentell data f¨or Fe-Ni bulklegeringar f¨or att kunna verifiera modellernasnoggrannhet och att det ¨ar m¨ojligt att f¨oruts¨aga egenskaperna hos h°ardmetall.
Bakke, Eric Johnson W. L. "Viscosity measurements of bulk metallic glass forming alloys /." Diss., Pasadena, Calif. : California Institute of Technology, 1997. http://resolver.caltech.edu/CaltechETD:etd-01042008-090419.
Повний текст джерелаScarfone, Roberto. "Mechanical spectroscopy of Zr-based bulk glass forming alloys." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=964907925.
Повний текст джерелаSaltoglu, Ilkay. "Synthesis And Characterization Of Zirconium Based Bulk Amorphous Alloys." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/1260455/index.pdf.
Повний текст джерелаhigh tensile strength, high fracture toughness, high corrosion resistance and good machinability. In this study, the aim is to model, synthesize and characterize the Zr-based bulk amorphous alloys. Initially, theoretical study on the basis of the semi-empirical rules well known in literature and the electronic theory of alloys in pseudopotential approximation has been provided in order to predict the potential impurity elements that would lead to an increase in the GFA of the selected Zr-Ni, Zr-Fe, Zr-Co and Zr-Al based binary systems. Furthermore, thermodynamic and structural parameters were calculated for mentioned binary and their ternary systems. According to the theoretical study, Zr67Ni33 binary system was selected and its multicomponent alloys were formed by adding its potential impurity elements
Mo, W and Al. Centrifugal casting method was used to produce alloy systems. Structural characterizations were performed by DSC, XRD, SEM and EDS methods. In the near-surface regions of Zr60Ni25Mo10W5 and Zr50Ni20Al15Mo10W5 alloys, amorphous structure has been observed. Experimental studies have shown that Zr-Ni based systems with impurity elements Mo, W and Al, not widely used in literature, might be good candidates for obtaining high GFA.
Arslan, Hulya. "Synthesis And Characterization Of Nickel Based Bulk Amorphous Alloys." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/12605099/index.pdf.
Повний текст джерелаAybar, Sultan. "Solidification And Crystallization Behaviour Of Bulk Glass Forming Alloys." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608922/index.pdf.
Повний текст джерелаBossuyt, Sven. "Microstructure and crystallization behavior in bulk glass forming alloys." Diss., Pasadena, Calif. : California Institute of Technology, 2001. http://resolver.caltech.edu/CaltechETD:etd-07022001-164944.
Повний текст джерелаAyas, Can. "Theoretical And Experimental Investigation Of Bulk Glass Forming Ability In Bulk Amorphous Alloy Systems." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605884/index.pdf.
Повний текст джерелаZeagler, Andrew. "On a Bimodal Distribution of Grain Size in Mechanically Alloyed Bulk Tungsten Heavy Alloys." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/77119.
Повний текст джерелаPh. D.
Wang, Xiaowei. "Thermoelectric property studies on nanostructured N-type Si-Ge Bulk Materials." Thesis, Boston College, 2009. http://hdl.handle.net/2345/2504.
Повний текст джерелаSiGe alloys are the only proven thermoelectric materials in power generation devices operating above 600 °C and up to 1000 °C in heat conversion into electricity using a radioisotope as the heat source. In addition to radioisotope applications, SiGe thermoelectric materials have many other potential applications, for example, solar thermal to electricity energy conversion and waste heat recovery. However, traditional SiGe alloy material shows low ZT values of about 0.93 at 900 °C, thus, 8% is the highest device efficiency for commercial SiGe thermoelectric devices. Recently, many efforts have been made to enhance the dimensionless thermoelectric figure-of-merit (ZT) of SiGe alloys. Among them, the nano approach has been recognized as an effective mechanism to obtain thermoelectric materials with good performance. In this approach, dense bulk samples with random nanostructures with high interface densities are synthesized through ball milling and a direct current hot press, leading to an enhancement ZT through reduced phonon thermal conductivity. Such a practical technique produced samples of nanostructured p-type dense bulk bismuth antimony telluride with a peak ZT of 1.4 at 1000 °C from either alloy ingot or elemental chunks. However, the generality of this approach has not been demonstrated. Here, we applied the same technique in SiGe system in order to fabricate a nanostructured n-type SiGe alloy with enhanced thermoelectric properties. In this thesis, numerous nanostructured n-type SiGe alloy samples were successfully pressed. The structure of these nanostructured samples was investigated via XRD, EDS, and TEM. It has been confirmed that many nano grains exist in our nanostructured samples
Thesis (PhD) — Boston College, 2009
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Physics
Baliga, Chaitanya B. "Bulk and surface studies of rapidly solidified Mg Al alloys." Thesis, University of Surrey, 1990. http://epubs.surrey.ac.uk/843174/.
Повний текст джерелаMridha, Sanghita. "Structure Evolution and Nano-Mechanical Behavior of Bulk Metallic Glasses and Multi-Principal Element Alloys." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc984260/.
Повний текст джерелаAyyagari, Venkata A. "Surface Degradation Behavior of Bulk Metallic Glasses and High Entropy Alloys." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc1062863/.
Повний текст джерелаErdiller, Emrah Salim. "Investigation Of Solidification And Crystallization Of Iron Based Bulk Amorphous Alloys." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/1096585/index.pdf.
Повний текст джерела#65533
Based bulk amorphous alloys, to synthesize Fe &
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based multicomponent glassy alloys by using the predictions of the theoretical study, and to analyze the influence of crystallization and solidification kinetics on the microstructural features of this amorphous alloys. For this purpose, first, glass forming ability of Fe &
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(Mo, B, Cr, Nb, C) &
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X ( X = various alloying elements, selected from the periodic table) ternary alloy systems were simulated for twenty different alloy compositions by using the electronic theory of alloys in pseudopotential approximation and regular solution theory. Then, by using the results of the theoretical study, systematic casting experiments were performed by using centrifugal casting method. The alloying elements were melted with induction under argon atmosphere in alumina crucibles and casted into copper molds of different shapes. Characterization of the cast specimens were performed by using DSC, XRD, SEM, and optical microscopy. Comparison of equilibrium and nonequilibrium solidification structures of cast specimens were also performed so as to verify the existence of the amorphous phase. Good agreement of the results of experimental work, with the predictions of the theoretical study, and the related literature was obtained.
Suer, Sila. "Investigations On Bulk Glass Forming Ability Of Titanium Based Multicomponent Alloys." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609656/index.pdf.
Повний текст джерелаPark, Mansoo Ph D. Massachusetts Institute of Technology. "Design of bulk nanocrystalline tungsten alloys via nano-phase separation sintering." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98166.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (pages 96-100).
An accelerated sintering method called 'nano-phase separation sintering' is developed, with specific applicability to nanostructured tungsten alloys. Nanocrystalline tungsten alloys containing minority additions of chromium are produced by high-energy ball milling and then consolidated. Such alloys exhibit the onset of sintering at a very low temperature around 950 °C and a very rapid rate of densification. The mechanism of this accelerated sintering is established through understanding the role of nano-scale, solid second phase precipitation during the sintering cycle, as analyzed by thermomechanical analysis, electron microscopy and x-ray diffraction. In addition, control experiments are used to establish that the accelerated sintering is apparently accomplished from the combination of two features of the powders: (i) nanocrystallinity and (ii) alloy supersaturation. In addition to accelerating sintering, the incorporation of alloying elements and second phases are also beneficial for mitigating grain growth during a thermal cycle, so nanophase separation sintering is thus naturally appropriate to the production of fine-grained bulk materials. Sintered compacts achieved through nano-phase separation sintering display 10~30 times smaller grain sizes at comparable densities than those produced by conventional accelerated sintering methods such as solid-state activated sintering and liquid phase sintering. The thermodynamic features and conditions for nano-phase separation sintering are further explored based on the binary phase diagram in order to generalize the concept to other alloy systems. After presenting a series of proposed alloy design rules, the consolidation of chromium with an addition of nickel is accelerated. Prospects of the technique for the development of full density bulk products in more complex alloy systems are also discussed.
by Mansoo Park.
Ph. D.
Rounthwaite, Nicholas James. "Development of bulk nanoquasicrystalline alloys for high strength elevated temperature applications." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:47bdc219-1733-40c1-ac6b-dbd5fc08f175.
Повний текст джерелаDiplas, Spyridonas. "Bulk surface studies of vapour deposited Mg-V and Mg-Zr alloys." Thesis, University of Surrey, 1998. http://epubs.surrey.ac.uk/844498/.
Повний текст джерелаKlaer, Peter [Verfasser]. "Spectroscopic investigations of functional bulk and thin film Heusler alloys / Peter Klaer." Mainz : Universitätsbibliothek Mainz, 2012. http://d-nb.info/1024307131/34.
Повний текст джерелаTian, Liyun. "Density Functional Theory Study of Bulk Properties of Metallic Alloys and Compounds." Doctoral thesis, KTH, Tillämpad materialfysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210305.
Повний текст джерелаQc 20170630
Waniuk, Theodore Andrew Johnson W. L. "Viscosity and crystallization in a series of Zr-based bulk amorphous alloys /." Diss., Pasadena, Calif. : California Institute of Technology, 2004. http://resolver.caltech.edu/CaltechETD:etd-06102004-214551.
Повний текст джерелаAbdelal, Ali. "Synthesis And Characterization Of Ti-based Bulk Amorphous/nanocrystalline Alloys For Engineering Applications." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/1096338/index.pdf.
Повний текст джерела#916
HM, viscosity, mismatch entropy, Rc was calculated for various Ti-based binary and ternary and the change in these parameters in both cases was evaluated. The results of the theoretical calculations of glass forming parameters has shown good relation with the literature data that the predicted alloying elements, i.e. Mo, Hf, Zr, B, Fe, Sn, and Be, to increase GFA for Ti2Ni binary system were generally used in the production of Ti-based bulk amorphous alloys. In the second part of this thesis, new Ti-based compositions with high GFA were tried to be synthesized with light of these results and encouraging conclusions were drawn. The production of these alloys were made with centrifugal casting method which is relatively a new technique for producing such alloys and the characterization of these alloys were made with metallographic, X-ray and thermal means.
Wei, Shuai [Verfasser], and Ralf [Akademischer Betreuer] Busch. "Kinetic, thermodynamic, and structural transitions in order-disorder alloys and bulk metallic glass-forming alloys / Shuai Wei. Betreuer: Ralf Busch." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2014. http://d-nb.info/1059390515/34.
Повний текст джерелаAtzmon, M. Johnson W. L. "A study of bulk amorphous alloys formed by solid-state reaction in elemental composites /." Diss., Pasadena, Calif. : California Institute of Technology, 1986. http://resolver.caltech.edu/CaltechETD:etd-03212008-081007.
Повний текст джерелаAyyagari, Venkata Aditya. "Effect of Alloy Composition, Free Volume and Glass Formability on the Corrosion Behavior of Bulk Metallic Glasses." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc822824/.
Повний текст джерелаGurbuz, Selen Nimet. "Synthesis And Characterization Of Bulk Glass-forming Iron-boron Based Alloy Systems." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/12605103/index.pdf.
Повний текст джерелаZiółkowski, Grzegorz. "Structural and physical properties of Fe-Nb-B-RE type of bulk magnetic nanocrystalline alloys." Doctoral thesis, Katowice : Uniwersytet Śląski, 2015. http://hdl.handle.net/20.500.12128/5907.
Повний текст джерелаTrivedi, Yash Nipun. "Investigation of Mechanical Properties of Bulk and Additively Manufactured Ni-Mn-Ga Shape Memory Alloy using Nanoindentation and Microhardness Techniques." Youngstown State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1558656191440726.
Повний текст джерелаGu, Zheng. "Sublimation growth of AlN-SiC alloys, AlN and ScN bulk crystals, and thermal oxidation of AlN /." Search for this dissertation online, 2006. http://wwwlib.umi.com/cr/ksu/main.
Повний текст джерелаPandey, Sudip. "EXPLORING THE STRUCTURAL, ELECTRONIC, AND MAGNETORESPONSIVE PROPERTIES OF NOVEL MAGNETIC MATERIALS IN BULK, RIBBONS, AND THIN FILMS." OpenSIUC, 2019. https://opensiuc.lib.siu.edu/dissertations/1682.
Повний текст джерелаSwaminathan, S. "Processing And Characterisation Of Bulk Al2 O3 p /AIN-Al Composites By Pressureless Infiltration." Thesis, Indian Institute of Science, 2000. http://hdl.handle.net/2005/181.
Повний текст джерелаGargarella, Piter. "Phase formation, thermal stability and mechanical behaviour of TiCu-based alloys." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-133969.
Повний текст джерелаAuf Grund der hohen Elastizitätsgrenze, Festigkeiten, die nahe an der theoretischen Grenze liegen, sehr guten magnetischen Eigenschaften, sowie einer guten Korrosionsbeständigkeit erscheint der Einsatz massiver metallischer Gläser (BMG) vielversprechend in zahlreichen Gebieten, wie z.B. in Mikro-Getriebemotorteilen, Coriolis-Massendurchflussmessern, Drucksensoren, Speicherdrosseln und als Beschichtungsmaterialien. Der Einsatz dieser Materialien wird jedoch hauptsächlich durch ihre begrenzte makroskopische Duktilität bei Raumtemperatur eingeschränkt. Diese resultiert aus einer inhomogenen Verformung, die in schmalen Scherbändern konzentriert ist. Die unzureichende Duktilität kann durch das Einbringen einer zweiten, duktilen Phase in die Glas-Matrix verbessert werden, so dass Komposite gebildet werden. Diese Komposite weisen in der Regel immer noch hohe Festigkeiten auf, lassen sich aber gleichzeitig deutlich besser plastisch verformen. Es wurden bereits verschiedene Arten von massiven metallischen Glas-Matrix-Kompositen entwickelt. Jedoch konnte die plastische Verformbarkeit in Zug- oder Biegeversuchen nur in den Materialien erhöht werden, in denen sich die zweite Phase bei der Erstarrung ausscheidet. Unter diesen in-situ Kompositen konnte eine signifikante Duktilität lediglich für zwei Legierungstypen beobachtet werden: massive metallische Gläser auf TiZrBe- und auf CuZr-Basis. Die Ausscheidungen der kubischen β-(Ti,Zr) Phase wachsen dendritenartig in die Glas-Matrix, wohingegen sich in letzterem Legierungstypen sphärische Ausscheidungen der Formgedächtnislegierung, B2-CuZr, im Glas bilden. CuZr-Basislegierungen haben dabei den großen Vorteil, dass sie kein Be enthalten, welches toxisch ist. Außerdem weisen diese Komposite auch dank der Formgedächtnisphase eine starke Kaltverfestigung auf. Das Konzept, massive metallische Formgedächtnis-Glas-Matrix-Komposite herzustellen, um die mechanischen Eigenschaften zu optimieren, wurde bisher nur auf CuZr-Basislegierungen angewandt. Es soll mittels dieser Arbeit nun erforscht werden, ob dieses Konzept auf andere massive metallische Gläser übertragbar ist. Des Weiteren ist der Zusammenhang zwischen Gefüge, Phasenbildung und mechanischen Eigenschaften der Komposite noch nicht vollständig verstanden, insbesondere die Rolle der Ausscheidungen in Bezug auf die Scherbandbildung und die Spannungsverteilung in der Glas-Matrix. Das Ziel der vorliegenden Arbeit ist die Entwicklung einer neuen Klasse massiver, metallischer Formgedächtnis-Glas-Matrix Komposite um das Konzept, welches ursprünglich für CuZr-Basislegierungen entwickelt wurde, zu erweitern. Die thermischen und mechanischen Eigenschaften sollen mit dem Gefüge und der Phasenbildung in Beziehung gesetzt werden, um so die fundamentalen Verformungsmechanismen und ihre Ursachen besser zu verstehen. Der Ausgangspunkt bei der Herstellung neuer massiver metallischer Formgedächtnis-Glas-Matrix Komposite ist das pseudobinäre TiCu-TiNi-System. In diesem System konnten massive Glasproben mit einem kritischen Gießdurchmesser von circa 1 mm hergestellt werden und zwar in dem Zusammensezungsbereich, in dem die kubische Formgedächtnisphase, B2-TiNi, gebildet wird. Während der Abkühlung findet in diesen Kompositen bei etwa 325 K eine martensitische Umwandlung der B2-Phase zur orthorhombischen B19-TiNi Phase statt. B2- und B19-TiNi weisen eine gute Verformbarkeit von bis zu 30% bei Raumtemperatur unter Zugbelastung auf. Die hier erzeugten Ti-Cu, Ti-Cu-Ni, Ti-Cu-Ni-Zr, Ti-Cu-Ni-Zr-(Si) und Ti-Cu-Ni-Co-Legierungen basieren auf Literaturangaben und Vorhersagen bezüglich der Glasbildungsfähigkeit in diesen Systemen mittels λ+Δh1/2-Kriterium, welches die Auswirkungen der Atomgrößenunterschiede der Elemente und deren elektronische Wechselwirkung einbezieht. Die Proben wurden im Schmelzspinnverfahren (Bänder) und mittels Saugguss in einer Cu-Kokille (Stäbe und Bleche) hergestellt. Die Weiter- und Neuentwicklung von Legierungen, beginnt mit dem Ti-Cu-System. Die Glasbildungsfähigkeit in diesem binären System ist nur gering, so dass lediglich mikrometerdicke amorphe Bänder hergestellt werden können. Die Ergebnisse zeigen, dass der beste Glasbildner eine Zusammensetzung von etwa Ti50Cu50 hat. Die Glasbildungsfähigkeit von binären Legierungen kann durch die Zugabe von Ni weiter verbessert werden. Dies führte innerhalb dieser Arbeit zur Entwicklung neuer Ti-Cu-Ni Formgedächtnis-Glas-Matrix Komposite, in welchen die orthorhombische Martensitphase in der Glas-Matrix ausgeschieden wird. Diese ternären Legierungen zeigen eine hohe Zugfestigkeit in Kombination mit einer hohen Bruchdehnung. Beim Überschreiten einer Temperatur von etwa 320 K vollziehen die Ausscheidungen eine reversible martensitische Umwandlung vom B19- zum B2-Strukturtyp. Durch die amorphe Matrix wird die Hochtemperaturphase (B2 Phase) stabilisiert. Dies verursacht unterschiedliche Umwandlungstemperaturen im Kompositmaterial, die davon abhängig sind, ob die Ausscheidungen nur teilweise oder vollständig in der Matrix eingebettet sind. Die Verformung beginnt in der weichen kristallinen Phase, welche eine heterogene Spannungsverteilung in der Glas-Matrix erzeugt und eine hohe Dichte an Scherbändern in der Matrix verursacht. Die Ausscheidungen haben zudem die Funktion, die Ausbreitung der Scherbänder zu blockieren und das Versagen des Materials zu verzögern. Die Größe der Komposite ist jedoch auf Grund der geringen Glasbildungsfähigkeit auf einen Stabdurchmesser von ca. 1 mm begrenzt. Dies kann mit dem Zulegieren von CuZr verbessert werden. Es wurden hier auf diese Weise neue Ti-Cu-Ni-Zr Komposite entwickelt, deren Durchmesser zwischen 2 und 3 mm liegt. Diese bestehen hauptsächlich aus sphärischen Ausscheidungen der kubischen B2-(Ti,Zr)(Cu,Ni)- und der Glasphase. Die wechselseitige Beziehung zwischen der Streckgrenze und dem Volumenanteil der B2-Phase wurde im Detail untersucht. Für kristalline Volumenanteile kleiner als 30 Vol.-% folgt die Streckgrenze der Mischungsregel und für größere Volumenanteile dem „lasttragenden Modell“ (load bearing model). Die Bruchdehnung wird ebenfalls vom Volumenanteil der Phasen beeinflusst und zeigt ein Maximum bei etwa 30 Vol.-% an B2-Phase. Dies stimmt mit der Vorhersage des „Drei-Element-Modells“ überein. Es wurde festgestellt dass die kubische B2-Phase während der Verformung eine martensitische Umwandlung durchführt, was die starke Kaltverfestigung und die hohen Bruchspannungen dieser Legierungen zur Folge hat. Die Glasbildungsfähigkeit von TiCu-Basislegierungen kann im Gegenzug weiterhin durch geringe Si-Zusätze gesteigert werden. Hierbei tritt jeweils ein Maximum bei Zusätzen von 1 und 0,5 at-% Si zu binären Ti-Cu- oder zu quarternären Ti-Cu-Ni-Zr-Legierung auf. Das Optimum der Glasbildungsfähigkeit ist das Ergebnis sowohl eines geringeren Anteils hochschmelzender Ti5Si3-Ausscheidungen, die als Keimbildner für andere kristalline Phasen dienen, als auch der erhöhten Stabilität der Schmelze sowie der unterkühlten Schmelze. Der Zusatz von Co wiederum hat einen gegenteiligen Effekt. Er vermindert die Glasbildungsfähigkeit von Ti-Cu-Ni-Legierungen drastisch. Zudem scheinen sowohl die martensitische Umwandlungstemperatur als auch das mechanische Verhalten mit der Zahl und Konzentration der Valenzelektronen der B2-Phase zu korrelieren. Die Umwandlungstemperatur sinkt mit steigender Valenzelektronenkonzentration. Eine ausgezeichnete Kombination von hoher Streckgrenze und Bruchdehnung tritt für die Legierungen Ti-Cu-Ni-Zr und Ti-Cu-Ni-Zr-Si mit einem relativ geringen CuZr-Anteil auf. Die Bruchdehnung unter Druck ist fast zweimal höher als es für CuZr-Basis-Komposite gewöhnlich beobachtet worden ist. Die Legierung Ti45Cu39Ni11Zr5 zeigt beispielsweise eine Streckgrenze von 1490±50 MPa in Kombination mit einer plastischen Dehnung von 23,7±0,5%. Für die CuZr-reicheren Ti-Cu-Ni-Zr Zusammensetzungen wurde jedoch eine geringere Duktilität festgestellt, was das Resultat spröder Cu2TiZr-Ausscheidungen in der Glas-Matrix ist. Die vorliegende Arbeit erweitert folglich das Konzept der „Formgedächtnis-Glas-Matrix Komposite“, welches bisher auf CuZr-basierte Legierungen beschränkt war und liefert wichtige Einblicke in die Beziehung zwischen Phasenbildung und mechanischen Eigenschaften der neuen Klasse hochfester TiCu-Basislegierungen, welche nach weiterer Optimierung vielversprechend sein könnten für Hochleistungsanwendungen wie Durchflussmesser, Sensoren und mikrometer- und mm-große Antriebe
Liao, Hao-Hsiang. "Thermal and thermoelectric properties of nanostructured materials and interfaces." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/19198.
Повний текст джерелаPh. D.
Duman, Nagehan. "Magnetic Monitoring Approach To Kinetics Of Phase Transformations In Multicomponent Alloy Systems." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614251/index.pdf.
Повний текст джерелаMathabathe, Maria Ntsoaki. "The development and microstructural evolution of the bulk yTi-45Al-2Nb (Sn Cr Mn & Si)-doped intermetallic alloys and their mechanical properties." Thesis, University of Pretoria, 2019. http://hdl.handle.net/2263/77843.
Повний текст джерелаThesis (PhD)--University of Pretoria, 2019.
Materials Science and Metallurgical Engineering
PhD
Unrestricted
Salajegheh, Nima. "Microstructure-sensitive weighted probability approach for modeling surface to bulk transition of high cycle fatigue failures dominated by primary inclusions." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/44709.
Повний текст джерелаJayatunga, Benthara Hewage Dinushi. "Heterovalent Semiconductors: First-Principles Calculations of the Band Structure of ZnGeGa2N4, and Metalorganic Chemical Vapor Deposition of ZnGeN2 - GaN Alloys and ZnSnN2." Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1619087038602758.
Повний текст джерелаBellina, Paul J. "High-temperature oxidation of bulk RuAl alloy." Stuttgart Max-Planck-Inst. für Metallforschung, 2006. http://deposit.d-nb.de/cgi-bin/dokserv?idn=980343135.
Повний текст джерелаAntonysamy, Alphons Anandaraj. "Microstructure, texture and mechanical property evolution during additive manufacturing of Ti6Al4V alloy for aerospace applications." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/microstructure-texture-and-mechanical-property-evolution-during-additive-manufacturing-of-ti6al4v-alloy-for-aerospace-applications(03c4d403-822a-4bfd-a0f8-ef49eb65e7a0).html.
Повний текст джерелаMao, Fang. "Synthesis, Characterization, and Evaluation of Ag-based Electrical Contact Materials." Doctoral thesis, Uppsala universitet, Oorganisk kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-320235.
Повний текст джерелаMonsegue, Niven. "Solid State Synthesis of Bulk Amorphous Ni – 50AT% Ti Alloy." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/31129.
Повний текст джерелаMaster of Science
Guan, Dikai. "Processing, microstructure and mechanical behavior of bulk nanostructured Mg alloy." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/11859/.
Повний текст джерелаLin, Chih-Yuan, and 林致遠. "Fe-Based Bulk Amorphous and Bulk Nanocrystalline Soft Magnetic Alloys." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/98748782430301425685.
Повний текст джерела國立清華大學
材料科學工程學系
95
This work focused on the development and study of Fe-based soft magnetic bulk metallic glasses (BMGs) and a strategy to produce bulk nanocrystalline alloys (BNCAs). Ternary Fe-based bulk metallic glasses were for the first time in the world developed. The BMG research contains two parts: (1) Ternary Fe-R-B (R= Sc, Y, Dy, Ho and Er). (2) Quaternary, Fe-(Co or Ni)-Y-B and Fe-Y-(Nb or Ta)-B BMG systems. Thermal properties, glass forming ability and magnetic properties were investigated. Ternary Fe-based BMGs represented by the formulae FeaMbBc are based on two simple selection rules: (1) M is an element with atomic radius at least 130% that of Fe; (2) M possesses an eutectic point with Fe and the M-Fe eutectic is at the Fe-rich end. The M elements, Sc, Y, Dy, Ho and Er fulfill the two rules exhibit BMG capability at the wide composition range, in atomic %, 3 < b < 10, 18< c < 27, whereas a+b+c = 100. It is much remarkable that bulk amorphous state is achievable with only 3 elements (conventional ones 4 to 7 elements). The ternary BMGs thus developed are characteristic of high saturation magnetization 1.2 to 1.56 T, low coercivity less than 40 A/m, and high electrical resistivity, larger than 200 microphm-cm. Among the explored ternary BMGs, Fe-Y-B alloys show the highest saturation magnetization 1.56 T. The properties of subsequently modified Fe-Y-B by Co, Ni and other transition metal (Nb and Ta) were also investigated. It shows a wide composition range retaining the BMG capability while replacing Fe by Co or Ni revealing a great advantage in modifying the magnetic properties to suit various industrial applications. The partial replacement of Y by Nb or Ta greatly improves the GFA and also retains the soft magnetic properties. The reduction of Y content to decrease the high chemical reactivity to improve industrial production is achieved. The Fe-Y-Nb-B and Fe-Y-Ta-B BMG exhibits extreme high compressive strength above 4000 MPa. New bulk nanocrystalline alloys were successfully achieved in Fe-Y-Nb-Cu-B, Fe-Si-B-Nb and Cu-Zr-Al alloy systems according to proposed “crystallization-and stop” model including (1) there is at least one principal element (PE) that dominates the crystallization temperature (Tx) and the Tx increases steeply with PE concentration, (2) the PE is barely soluble in the primary crystallites so that they pile up around the crystallizing nano-grains hence the Tx is manifestly increased locally, (3) once the increased Tx is higher than the raised sample temperature (due to heat of crystallization), the crystallization will be stopped to maintain a nano-grain structure, and (4) a nucleation agent is much helpful to enhance nucleation frequency hence reduce the resultant nano-sizes. The development of this model unveils a simpler and more practical way to design an alloy which can achieve bulk nanocrystallization.
Wu, Ming-Yuan, and 吳明遠. "Magnetostriction Study of FeMnGa Alloys in Bulk Form." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/4x6hpc.
Повний текст джерела國立臺灣海洋大學
光電科學研究所
102
Magnetostrictive materials have potential applications to MEMS and other sensing devices, because of their capabilities to convert magnetic energy into mechanical energy, and vice versa. This study focuses on a series of Fe81-xMnXGa19(x=0、3、8、13、18、23) bulks. First of all, deployed the weight of Fe、Mn、Ga, fuse the Fe、Mn、Ga by ARC and made into ingots, then use the WEDM cut into bulks. Structural property was investigated by X-ray diffraction (XRD) and magnetic property by vibration sample magnetometer (VSM). Magnetoelastic and magnetostriction were studied by using strain gauges. In the result of VSM measurement show that coercive force (i.e. HC) is increasing with x increasing. In other words, magnetic dipoles are harder to be flipped ever by reversing H with more and more Manganese. The VSM measurement also show the saturation magnetization (i.e. Ms) is decreasing with x increasing, when x=18 it chnage from ferromagnetic to paramagnetic. In the pat of measured magnetostriction, we used the train-gauge method. As the result, the magnetostriction of the Fe81Ga19 bulk is the largest, and decreasing with x increasing. In order to improve results, we use the furnace to anneal the sample made by 850℃ for 3 hours. Then measure those sample by VSM、SEM-EDS、XRD, compare the result of as cast sample and anneal sample.
Jhang, Fong-Lin, and 張豐麟. "Mechanical Properties of FeNiGa Alloys in Bulk Form." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/37598463020256993426.
Повний текст джерела國立臺灣科技大學
機械工程系
102
Magnetostrictive materials have potential applications to MEMS and other sensing devices, because of their capabilities to convert magnetic energy into mechanical energy, and vice versa. This study focuses on a series of Fe81-XNiXGa19(X =0、4、11、17、22、26) bulk. We examined the bulk components by SEM-EDS. Structural property was investigated by X-ray diffraction (XRD) and magnetic property by vibration sample magnetometer (VSM). Magnetostriction were studied by using strain gauges. Mechanical properties were using by Resonant Frequency &; Damping Analyser (RFDA) at Magnetic field measured. After analyzing via the above-listed instrument, the Fe81-XNiXGa19(X=0,4,11,17,22,26) bulks grow with the <110>&;<220> texture. About resistivity, samples with composition X=4 have larger resistivity. About magnetization, the measured saturation magnetization decrease with increases in Ni for Fe81-xNixGa19 alloys. As to the magnetostrictive part, the magnetostriction value has been decrease when the Nickel increases. In the mechanical properties part, the Young's modulus and shear modulus increases with the magnetic field becomes larger, the comparative hardness found in 0% Ni and 26% Ni has pretty good mechanical properties.
Bakke, Eric. "Viscosity measurements of bulk metallic glass forming alloys." Thesis, 1997. https://thesis.library.caltech.edu/27/1/Bakke_e_1997.pdf.
Повний текст джерелаYang, Yu-Min, and 楊瑜民. "The Study of Cu-based Bulk Amorphous Alloys." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/07334818149514038329.
Повний текст джерела國立清華大學
材料科學工程學系
95
The purpose of this study was to explore binary and ternary Cu-based bulk metallic glasses (BMG), which were divided into three systems: Cu-Hf-Al, Cu-Y-(M), Cu-Ti-M alloys, where M is an additive element. First, high Cu-content binary Cu-Hf BMG modified with Al, (Cu65Hf35)100-xAlx (x= 1, 2, 3, 4, 6) were studied. With only x= 2, the glass-forming ability (GFA) is greatly improved to form bulk glassy rod up to at least 3 mm in diameter. The microstructure consists of inhomogeneous amorphous phases. The Cu-Y binary system was chosen to study the GFA on compositions around the eutectic points and their modification. The microstructure of as-cast Cu-Y rods contained amorphous and crystalline mixture phases. According to the XRD results the best glass forming alloy is Cu78Y22. The further addition of Ag improves the GFA. The composition (Cu78Y22)97Ag3 was very close to form fully 1 mm BMG rod. Finally, we tried to develop the ternary BMGs based on high Cu content Cu-Ti BMG. The best result is the Cu50Ti40Zr10 glassy rod with the diameter at least 1 mm. The Cu-Y-M ternary alloys are brittle and poor electrochemical resistance due to their structure that contained amorphous and crystalline phases. Fully amorphous Cu-Hf-Al system showed the best mechanical properties with a compressive fracture strength up to 2340 MPa and a plastic strain up to about 1 % due to the inhomogeneous amorphous phases. Cu50Ti40Zr10 alloy performed low corrosion current density, 10-5 A/cm2, in 1 N H2SO4 + 0.01 N NaCl solution showed excellent electrochemical property, and its compressive fracture strength is up to about 2000 MPa.
Hsieh, Tsung Yen, and 謝宗諺. "Magnetostriction Study of FeCoGa Alloys in Bulk Form." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/67523250785735253057.
Повний текст джерела國立臺灣海洋大學
光電科學研究所
99
The magnetostrictive materials are potential for MEMS and device application, because of their capability to convert magnetic energy to mechanical energy. The thesis reports the magnetostriction of Fe81-xCoxGa19(x=0,7,11,19,23) bulks by arc-melting in annealing treatment. We examined the bulk components by SEM-EDS. The crystalline structure was analyzed by XRD. After analyzing via the above-listed instrument, we know that the Fe81-xCoxGa19(x=0,7,11,19,23) bulks grow with the <110> texture, we can know the structure of Fe81-xCoxGa19 bulks is body center cubic. About magnetization, the measured coercivity(HC) increases and saturation magnetization decrease with increases in Co for Fe81-xCoxGa19 alloys. As to the magnetostrictive part, the magnetostriction value has been decrease when the cobalt increases. In different conditions, 850°C SQW have more magnetostriction value than others. In other research, the magnetostriction value of the Fe81-XCoXGa19 thin films has been decreases. when the cobalt increases, but in this study didn't. Because of Fe81-xCoxGa19(x=0,7,11,19,23) bulks grow with the <200>and<211> texture more than thin films.
Kashyap, Sanjay. "Studies On Bulk And Multilayer Composites Of Nb-Si Alloys." Thesis, 2011. http://etd.iisc.ernet.in/handle/2005/2179.
Повний текст джерелаTULK, ERIC. "Bulk Hydrides and Delayed Hydride Cracking in Zirconium Alloys." Thesis, 2012. http://hdl.handle.net/1974/6969.
Повний текст джерелаThesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2012-01-24 06:14:14.152