Change search
Refine search result
1 - 46 of 46
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1.
    Baykov, Vitaly
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Jerlerud Perez, Rosa
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Korzhavyi, Pavel A.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Sundman, Bo
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Computational Thermodynamics.
    Johansson, Börje
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Structural stability of intermetallic phases in the Zr-Sn system2006In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 55, no 5, p. 485-488Article in journal (Refereed)
    Abstract [en]

    A thermodynamic description of the intermetallic compounds in the Zr-Sn binary system has been obtained using total energy calculations by means of the Vienna ab initio simulation package. Our calculations show that hexagonal compounds Zr5Sn4 and Zr5Sn3 are the most stable phases in the Zr-Sn binary system. Their high stability is found to be due to hybridization of the Sn 5p with Zr 4d electronic states. Based on the calculated energies, the conclusion is made that Zr substitution on the Sri sites takes place in the Zr4Sn phase, which accounts for the unusual stoichiometry of this Cr3Si structure type compound.

  • 2.
    Borgenstam, Annika
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Hillert, Mats
    KTH, Superseded Departments, Materials Science and Engineering.
    Model for nucleation of isothermal martensite2001In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 45, no 8, p. 917-922Article in journal (Refereed)
    Abstract [en]

    Kaufman and Cohen's model for thermally activated growth of preexisting embroys of isothermal martensite was defined with a series of obstacles but they only considered jumps in one direction. Jumps in both directions across obstacles were recently considered and the activation energy for the net reaction was described. That nucleation model is now developed further.

  • 3.
    Bu, Junfu
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Jönsson, Pär Göran
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Zhao, Zhe
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Shanghai Institute of Technology, China.
    Dense and translucent BaZrxCe0.8-xY0.2O3-delta (x=0.5, 0.6, 0.7) proton conductors prepared by spark plasma sintering2015In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 107, p. 145-148Article in journal (Refereed)
    Abstract [en]

    Dense and translucent BaZrxCe0.8-xY0.2O3-delta (x = 0.5, 0.6, 0.7) proton conductors were firstly and successfully prepared by Spark Plasma Sintering (SPS) at a temperature of 1350 degrees C without sintering aids' addition. XRD, SEM and EDS were applied to determine the phase purity, morphology and element composition of prepared pellets, respectively. Moreover, the sintering behaviors of these proton conductors were monitored and analyzed through the on-line sintering curves. The obtained results indicate that a lowered sintering temperature (<1400 degrees C) and a fast cooling rate (>= 200 degrees C/min) represent two key parameters to prepare dense Ce-containing BaZrO3-BaCeO3 based proton conductors.

  • 4.
    Bu, Junfu
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Jönsson, Pär Göran
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Zhao, Zhe
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Shanghai Institute of Technology, China.
    Electrical conductivities of translucent BaZr(X)Ce0.8-XY0.2O3-delta (x=0.5, 0.6, 0.7) ceramics2016In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 115, p. 87-90Article in journal (Refereed)
    Abstract [en]

    The electrical conductivities of translucent BaZr0.5Ce0.3Y0.2O3-delta (x = 0.5, BZCY532), BaZr0.6Ce0.2Y0.2O3-delta (x = 0.6, BZCY622) and BaZr0.7Ce0.1Y0.2O3-delta(x = 0.7, BZCY712) proton conductors were investigated systematically in different atmospheres and also at different oxygen partial pressures. The obtained results indicate that translucent BZCY532, BZCY622 and BZCY712 ceramics are pure oxygen-ion and proton conductors without unfavorable electronic conduction. In addition, they represent promising proton conductors to be used as intermediate temperature solid oxide fuel cell electrolytes.

  • 5. Edmondson, P. D.
    et al.
    Parish, C. M.
    Zhang, Y.
    Hallén, Anders
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Miller, M. K.
    Helium entrapment in a nanostructured ferritic alloy2011In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 65, no 8, p. 731-734Article in journal (Refereed)
    Abstract [en]

    A nanostructured ferritic alloy was irradiated with He+ to simulate service in a nuclear reactor and to test the hypothesis that the surface of nanoclusters is a preferential nucleation site for He bubbles. Transmission electron microscopy and atom probe tomography showed direct evidence of He bubble nucleation on the surfaces of nanoclusters and Ti(N,C) precipitates, and along grain boundaries and dislocations, thereby demonstrating an alloy design approach to improve the radiation tolerance of structural steels in the extreme environments found in nuclear reactors.

  • 6. Fashandi, H.
    et al.
    Andersson, M.
    Eriksson, J.
    Lu, J.
    Smedfors, Katarina
    KTH, School of Information and Communication Technology (ICT).
    Zetterling, Carl-Mikael
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Spetz, A. Lloyd
    Eklund, P.
    Single-step synthesis process of Ti3SiC2 ohmic contacts on 4H-SiC by sputter-deposition of Ti2015In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 99, p. 53-56Article in journal (Refereed)
    Abstract [en]

    We report a single-step procedure for growth of ohmic Ti3SiC2 on 4H-SiC by sputter-deposition of Ti at 960 degrees C, based on the Ti-SiC solid-state reaction during deposition. X-ray diffraction and electron microscopy show the growth of interfacial Ti3SiC2. The as-deposited contacts are ohmic, in contrast to multistep processes with deposition followed by rapid thermal annealing. This procedure also offers the possibility of direct synthesis of oxygen-barrier capping layers before exposure to air, potentially improving contact stability in high-temperature and high-power devices.

  • 7.
    Gorbatov, Oleg I.
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Nosov Magnitogorsk State Technical University, Russian Federation.
    Gornostyrev, Y. N.
    Korzhavyi, Pavel A.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Institute of Metal Physics, Russian Federation.
    Many-body mechanism of Guinier-Preston zones stabilization in Al–Cu alloys2017In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 138, p. 130-133Article in journal (Refereed)
    Abstract [en]

    Thermodynamics and atomic structures of pre-precipitates in dilute Al–Cu alloys are studied using Metropolis Monte Carlo simulations with many-body effective cluster interactions that have been systematically derived from ab initio supercell calculations. We show that many-body interactions, including the contributions due to lattice relaxations around the solute atoms, are mainly responsible for the formation of metastable planar atomic arrangements known as Guinier-Preston zones. Interaction terms up to four-body clusters are shown to be necessary to correctly reproduce the structures and temperatures of pre-precipitation in Al–Cu solid solutions.

  • 8.
    Gorbatov, Oleg I.
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Institute of Quantum Materials Science, Russian Federation.
    Gornostyrev, Yu. N.
    Institute of Quantum Materials Science, Russian Federation.
    Korzhavyi, Pavel A.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Institute of Metal Physics, Russian Federation .
    Ruban, Andrei V.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Materials Center Leoben, Austria .
    Effect of Ni and Mn on the formation of Cu precipitates in α-Fe2015In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 102, p. 11-14Article in journal (Refereed)
    Abstract [en]

    Decomposition in bcc Fe-Cu-Ni and Fe-Cu-Mn alloys is studied using statistical thermodynamics simulations with ab initio effective interactions. It is demonstrated that magnetic state strongly affects the effective interactions in these systems, substantially increasing phase separation tendency with magnetization. Simulations show that Ni is promoting precipitation of Cu by segregating to the precipitate matrix interface, while Mn produces almost no effect distributing more homogeneously in the system. The obtained distributions of Ni and Mn are in good agreement with experimental data.

  • 9.
    Gouldstone, Andrew
    et al.
    Dept. of Mat. Sci. and Engineering, Massachusetts Inst. of Technology.
    Wikström, Adam
    KTH, Superseded Departments, Solid Mechanics.
    Gudmundson, Peter
    KTH, Superseded Departments, Solid Mechanics.
    Suresh, Subra
    Dept. of Mat. Sci. and Engineering, Massachusetts Inst. of Technology.
    Onset of plastic yielding in thin metal lines deposited on substrates1999In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 41, no 3, p. 297-304Article in journal (Refereed)
    Abstract [en]

    A thermoelastic analysis of patterned lines on substrates to determine the critical conditions for the onset of yielding is investigated, which provides a new analytical tool for determining the yield properties of lines relative to those of films of the same thickness. Verification of the theory is provided with the aid of finite element simulations, and a method for experimentally extracting the plastic properties of lines is also outlined.

  • 10. Grönhagen, K.
    et al.
    Ågren, John
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Odén, M.
    Phase-field modelling of spinodal decomposition in TiAlN including the effect of metal vacancies2015In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 95, p. 42-45Article in journal (Refereed)
    Abstract [en]

    Using a CALPHAD approach together with a Cahn-Hilliard model, we describe the microstructure evolution in cubic Ti1-xAlxN including vacancies on the metal sublattice. Our results show that vacancy content has a pronounced effect on the decomposition kinetics. Furthermore, vacancies show a strong tendency to segregate to the coherent AlN-TiN interface regions. We illustrate how vacancies anneal to grain boundaries, and finally, we compare our prediction to experimental differential scanning calorimetry data and attribute the second peak in the thermogram to vacancy depletion.

  • 11. Hillert, M.
    et al.
    Odqvist, J.
    Ågren, John
    KTH, Superseded Departments, Metallurgy.
    Comparison between solute drag and dissipation of Gibbs energy by diffusion2001In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 45, no 2, p. 221-227Article in journal (Refereed)
    Abstract [en]

    The solute drag and the dissipation of Gibbs energy in a partitionless phase transformation are compared numerically. They agree if the solute drag is compared with the driving force over the interface and the solute spike in front of the interface. The dissipation can be evaluated over this whole region or over the interface alone.

  • 12.
    Hillert, Mats
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Comments on "Eutectic solidification of gray cast iron"2005In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 52, no 3, p. 249-250Article in journal (Refereed)
    Abstract [en]

    Applying a new technique for studying the orientation of austenite at room temperature, where it would normally transform to martensite, Rivera et al. have studied the solidification of gray cast iron. Their conclusions are in general agreement with the classical work in this field.

  • 13.
    Hillert, Mats
    KTH, Superseded Departments, Materials Science and Engineering.
    Nature of local equilibrium at the interface in the growth of ferrite from alloyed austenite2002In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 46, no 6, p. 447-453Article in journal (Refereed)
    Abstract [en]

    The increase over the years of experimental information on the effect of alloying elements on the transformation of austenite to ferrite and of the theoretical understanding is reviewed. The prediction of two kinds of transitions in behavior is described and the importance of exploring them experimentally is stressed.

  • 14.
    Hillert, Mats
    KTH, Superseded Departments, Materials Science and Engineering.
    Paradigm shift for bainite2002In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 47, no 3, p. 175-180Article in journal (Refereed)
    Abstract [en]

    One of the pictures of the mechanism of the bainitic transformation has been based upon the paradigm that it is closely related to the martensitic transformation. It has resulted in an unjustified belief in high growth velocity and high supersaturation of carbon in bainitic ferrite. It seems that the time is now right for abandoning that paradigm.

  • 15.
    Hillert, Mats
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Borgenstam, Annika
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Ågren, John
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Do bainitic and Widmanstatten ferrite grow with different mechanisms?2010In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 62, no 2, p. 75-77Article in journal (Refereed)
    Abstract [en]

    Caballero et al. recently presented new evidence for different growth mechanisms of Widmanstatten and bainitic ferrite. Their argument was based on Zener's hypothesis of diffusionless growth of bainitic ferrite. It is now demonstrated that Bhadeshia's model, based on Zener's hypothesis, predicts that some of the new measurements, claimed to fall above B-s and to be due to Widmanstatten ferrite, actually fall within the predicted temperature range of bainite, indicating that they cannot be used as new support for Bhadeshia's model.

  • 16.
    Hillert, Mats
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Höglund, Lars
    KTH, Superseded Departments, Materials Science and Engineering.
    Comments on kinetics model of isothermal pearlite formation in a 0.4C-1.6Mn steel2004In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 50, no 1, p. 171-173Article in journal (Refereed)
    Abstract [en]

    A recent attempt to use the volume fraction of isothermally formed pearlite to decide how Mn partitions between ferrite and cementite is criticized. An alternative method is proposed.

  • 17.
    Hillert, Mats
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Höglund, Lars
    KTH, Superseded Departments, Materials Science and Engineering.
    Comments on Reply to comments on kinetics model of isothermal pearlite formation in a 0.4C-1.6Mn steel2004In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 51, no 1, p. 77-78Article in journal (Refereed)
    Abstract [en]

    A recent statement that the correction of a serious error in a thermodynamic calculation was not relevant to the interpretation is shown to be caused by the use of an incorrect equation instead of the lever rule.

  • 18.
    Hillert, Mats
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Höglund, Lars
    KTH, Superseded Departments, Materials Science and Engineering.
    Melting of a peritectic phase2004In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 50, no 7, p. 1055-1059Article in journal (Refereed)
    Abstract [en]

    The reverse of a peritectic reaction belongs to the class of eutectic and eutectoid reactions and the same theory is now applied after modification for the fact that the predominating diffusion occurs within one of the growing phases, here the liquid one. The complications caused by the metastable congruent melting point are examined.

  • 19.
    Hillert, Mats
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Höglund, Lars
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Mobility of alpha/gamma phase interfaces in Fe alloys2006In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 54, no 7, p. 1259-1263Article in journal (Refereed)
    Abstract [en]

    Information on the mobility of alpha/gamma phase interfaces in Fe alloys has been scarce and one has long relied on an evaluation for alpha/alpha grain boundaries. New and old information is now reviewed. There are strong indications that the mobility is much lower than for alpha/alpha grain boundaries.

  • 20.
    Hillert, Mats
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Odqvist, Joakim
    KTH, Superseded Departments, Materials Science and Engineering.
    Ågren, John
    KTH, Superseded Departments, Materials Science and Engineering.
    Interface conditions during diffusion-controlled phase transformations2004In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 50, no 4, p. 547-550Article in journal (Refereed)
    Abstract [en]

    Considerations of the driving force on the interface in diffusional phase transformations are usually limited to diffusion in the parent phase. Diffusion in both phases is now considered. Equations are derived for the calculation of the composition of the material crossing the interface and the driving force acting on the interface.

  • 21.
    Hillert, Mats
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Selleby, Malin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Discussion of cementite layer formation and sooting2010In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 63, no 11, p. 1037-1040Article in journal (Refereed)
    Abstract [en]

    A thermodynamic explanation was recently proposed for the formation of massive layers of cementite without any graphite by gas carburization of steels at 550 degrees C if the gas contains NH(3). That explanation is now criticized. It is proposed that a kinetic factor, based on the difficulty of precipitating graphite inside a solid matrix, may contribute to the inhibition of metal dusting in the presence of NH3.

  • 22.
    Hillert, Mats
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Ågren, John
    KTH, Superseded Departments, Metallurgy.
    Discussion on local equilibrium at solid/liquid interfaces during melting2002In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 46, no 6, p. 455-457Article in journal (Refereed)
    Abstract [en]

    Melting experiments were recently used to support the assumption of considerable deviation from local equilibrium. It is now claimed that the observed velocities of melting were low enough to allow diffusion in the solid to give a well developed spike of the solute in front of the migrating interface making a strong deviation from local equilibrium unlikely.

  • 23.
    Hillert, Mats
    et al.
    KTH, Superseded Departments, Metallurgy.
    Ågren, John
    KTH, Superseded Departments, Metallurgy.
    On the definitions of paraequilibrium and orthoequilibrium2004In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 50, no 5, p. 697-699Article in journal (Refereed)
    Abstract [en]

    Hultgren's terminology of paraferrite and paracementite in alloy steels and his definition of paraequilibrium are reviewed. They are not completely compatible due to the possibility of forming ferrite with the initial alloy content (paraferrite) even under full local equilibrium (local orthoequilibrium). That has caused some confusion.

  • 24.
    Hillert, Mats
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Ågren, John
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Reply to comments on "On the definition of paraequilibrium and orthoequilibrium"2005In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 52, no 1, p. 87-88Article in journal (Refereed)
    Abstract [en]

    In the equilibrium conditions called CPE the letters PE stand for paraequilibrium. However, paraequilibrium plays no important role in the process for which CPE was introduced. The essential feature is the equilibration of carbon between a and γ under the constraint that the interface is immobile. In order to avoid confusion regarding the nature of paraequilibrium, the term CCE (constrained carbon equilibrium) is proposed instead of CPE.

  • 25. Hou, T. P.
    et al.
    Peet, Mathew James
    Hulme-Smith, Christopher
    University Of Cambridge.
    Wu, K. M.
    Li, Y.
    Guo, L.
    The determining role of magnetic field in iron and alloy carbide precipitation behaviors under the external field2016In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 120Article in journal (Refereed)
    Abstract [en]

    © 2016 Elsevier B.V. All rights reserved. A combined approach to calculate the thermodynamic properties of iron and alloy carbides including the thermal and magnetic contribution is derived. Special emphasis is placed on the role of Fe and Mo to the Gibbs free energy. Lower Mo concentration in the carbides corresponds to a higher thermal Gibbs free energy change. The higher Fe content and external magnetic field greatly increase the induced magnetization, reducing the magnetic Gibbs free energy substantially and therefore increase the formation temperature. The stability of M 2 C and M 3 C are mainly determined by the thermal factors, whereas magnetic field has a predominant contribution for M 6 C.

  • 26.
    Huang, Shuo
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Li, Wei
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Lu, Song
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Tian, Fuyang
    Univ Sci & Technol Beijing, Dept Phys, Beijing 100083, Peoples R China..
    Shen, Jiang
    Univ Sci & Technol Beijing, Dept Phys, Beijing 100083, Peoples R China..
    Holmstrom, Erik
    Sandvik Coromant R&D, S-12680 Stockholm, Sweden..
    Vitos, Levente
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics. Uppsala Univ, Div Mat Theory, Dept Phys & Astron, SE-75120 Uppsala, Sweden.
    Temperature dependent stacking fault energy of FeCrCoNiMn high entropy alloy2015In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 108, p. 44-47Article in journal (Refereed)
    Abstract [en]

    The stacking fault energy (SFE) of paramagnetic FeCrCoNiMn high entropy alloy is investigated as a function of temperature via ab initio calculations. We divide the SFE into three major contributions: chemical, magnetic and strain parts. Structural energies, local magnetic moments and elastic moduli are used to estimate the effect of temperature on each term. The present results explain the recently reported twinning observed below room-temperature and predict the occurrence of the hexagonal phase at cryogenic conditions.

  • 27.
    Hulme-Smith, Christopher
    et al.
    University Of Cambridge.
    Lonardelli, I.
    Dippel, A. C.
    Bhadeshia, Harshad Kumar Dharamshi Hansraj
    Experimental evidence for non-cubic bainitic ferrite2013In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 69, no 5, p. 409-412Article in journal (Refereed)
    Abstract [en]

    The first evidence is provided for the existence of a tetragonal or slightly orthorhombic unit cell of bainitic ferrite. It supports the hypothesis that the excess carbon that persists in the ferrite, which is in contact with austenite, is a consequence of an increased solubility due to the change in symmetry from the conventional cubic unit cell. The deviations from the cubic cell are maintained to elevated temperatures, as expected from an increased solubility of carbon in the ferrite.

  • 28.
    Hulme-Smith, Christopher
    et al.
    University Of Cambridge.
    Lonardelli, I.
    Peet, Mathew James
    Dippel, A. C.
    Bhadeshia, Harshad Kumar Dharamshi Hansraj
    Enhanced thermal stability in nanostructured bainitic steel2013In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 69, no 2, p. 191-194Article in journal (Refereed)
    Abstract [en]

    We report an attempt at increasing the thermal stability of nanocrystalline bainite to tempering heat treatments by enhancing the silicon concentration of the alloy. Validation experiments have been conducted using synchrotron X-irradiation during tempering heat treatment. It is found that the change in alloying successfully stabilizes the austenite at elevated temperatures by retarding cementite formation to temperatures as high as 500 ˚C. Other changes reflected in the lattice parameters of the major phases have revealed further information about the mechanisms involved.

  • 29. Kaufman, Larry
    et al.
    Ågren, John
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    CALPHAD, first and second generation - Birth of the materials genome2014In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 70, no 1, p. 3-6Article in journal (Refereed)
    Abstract [en]

    The "materials genome" was given a rather vague definition in US President Obama's announcement in 2011. We argue that the materials genome, analogously with biological genomes, should be defined as a set of information (databases) allowing prediction of a material's structure, as well as its response to processing and usage conditions. The materials genome is thus encoded in the language of CALPHAD thermodynamics and kinetics, as such databases are major parts of integrated computational materials engineering.

  • 30.
    Kese, Kwadwo
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Li, Zhi-Cheng
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Semi-ellipse method for accounting for the pile-up contact area during nanoindentation with the Berkovich indenter2006In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 55, no 8, p. 699-702Article in journal (Refereed)
    Abstract [en]

    A method of approximating the pile-up contact perimeter as a semi-ellipse originally developed for soda-lime glass, has been investigated for its applicability to other materials including work-hardened copper, Zr-based bulk metallic glass, strontium fluoroapatite, tungsten carbide, silicon nitride and aluminium oxide. The study revealed that all the materials formed pile-ups during nanoindentation. The elastic modulus and hardness values obtained after correcting for the pile-up contact area using the semiellipse approximation were,consistent with those found in the literature.

  • 31. Kim, D. K.
    et al.
    Zhang, Y.
    Voit, W.
    Kao, K. V.
    Kehr, J.
    Bjelke, B.
    Muhammed, Mamoun
    KTH, Superseded Departments, Materials Science and Engineering.
    Superparamagnetic iron oxide nanoparticles for bio-medical applications2001In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 44, no 09-aug, p. 1713-1717Article in journal (Refereed)
  • 32. Kodash, V. Y.
    et al.
    Groza, J. R.
    Aldica, G.
    Toprak, Muhammet
    Li, Shanghua
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Muhammed, Mamoun
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Field-activated sintering of skutterudites2007In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 57, no 6, p. 509-511Article in journal (Refereed)
    Abstract [en]

    Skutterudite (Co0.92Ni0.08)4Sb11.88Te0.12 powder has been consolidated under an applied electrical field using a field-assisted sintering technique (FAST). The low FAST sintering temperature and relatively high heating rate considerably reduce grain growth during sintering.

  • 33.
    Larsson, Henrik
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Borgenstam, Annika
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Trans-interface diffusivity in the Fe-Ni system2007In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 56, no 1, p. 61-64Article in journal (Refereed)
    Abstract [en]

    The trans-interface diffusivity in the Fe-Ni system has been estimated by fitting simulations to experimental data. For diffusion across the alpha/gamma phase boundary, the mobility of species divided by an interfacial thickness of 1 nm, M-k/delta, is approximately 5% of the phase interface mobility M-int at 873 K and 15% at 973 K.

  • 34.
    Larsson, Henrik
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Ågren, John
    KTH, Superseded Departments, Materials Science and Engineering.
    A random-walk approach to diffusion controlled growth2003In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 49, no 6, p. 521-526Article in journal (Refereed)
    Abstract [en]

    The new method does not require formulation of any special conditions at the moving phase interface. Although only binary systems are treated at present an extension to any number of components seems straightforward. A good agreement with conventional front tracking techniques (DICTRA) is found.

  • 35.
    Larsson, Henrik
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Ågren, John
    KTH, Superseded Departments, Materials Science and Engineering.
    A random-walk approach to diffusion controlled growth II: A distribution function solution2004In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 51, no 2, p. 137-140Article in journal (Refereed)
    Abstract [en]

    Earlier work on simulations of diffusion controlled transformations based on a random-walk technique is extended; a random-walk simulation of a transformation in a ternary system and a new method based on distribution functions are presented. As before, no special assumption regarding the state of the phase interface is required.

  • 36. Morral, J. E.
    et al.
    Pan, X. M.
    Zhou, N.
    Larsson, Henrik
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Wang, Y. Z.
    Singularities in multiphase diffusion couples2008In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 58, no 11, p. 970-972Article in journal (Refereed)
    Abstract [en]

    Singularities are not normally expected in diffusion couple data; however, they can occur in certain multiphase concentration profiles and diffusion paths. The following work reviews the theoretical reason why singularities form and gives two different computer simulations that support the theoretical predictions. In addition, a correction is given to a previous paper in which artifacts created by modeling software were inadvertently reported as diffusional singularities.

  • 37.
    Odqvist, Joakim
    Thermo-Calc Software AB.
    On the transition to massive growth during the γ->α transformation in Fe-Ni alloys2005In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 52, no 3, p. 193-197Article in journal (Refereed)
    Abstract [en]

    A newly developed procedure for calculating deviation from local equilibrium at phase interfaces, caused by dissipation of Gibbs energy due to diffusion inside the interface, was implemented in the DICTRA code. The austenite to ferrite transformation in Fe-Ni alloys and the transition to a massive transformation upon cooling is studied.

  • 38.
    Razumovskiy, Vsevolod I.
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Ruban, Andrei V.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Razumovskii, I. M.
    Lozovoi, A. Y.
    Butrim, V. N.
    Vekilov, Yu. Kh.
    The effect of alloying elements on grain boundary and bulk cohesion in aluminum alloys: An ab initio study2011In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 65, no 10, p. 926-929Article in journal (Refereed)
    Abstract [en]

    The effect of B, Si, P, Cr, Ni, Zr and Mg impurities on cohesive properties of Al and its special grain boundary (GB) Sigma 5 (2 1 0) [1 0 0], as well as their segregation behavior at the GB and (2 1 0) surface are studied from first principles. Our analysis determines Ni to be the best and P the worst alloying elements in regard to the overall resistance to decohesion of Al alloys.

  • 39. Schwind, M.
    et al.
    Helander, T.
    Ågren, John
    KTH, Superseded Departments, Metallurgy.
    On zigzag shaped diffusion paths in multi-phase diffusion couples2001In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 44, no 3, p. 415-421Article in journal (Refereed)
  • 40.
    Sterneland, Therese
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Xie, Jiaying
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Chen, N.-X.
    Seetharaman, Seshadri
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Solubility of Co in Cr7c3-Ab initio studies and experimental verification2006In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 54, no 8, p. 1491-1495Article in journal (Refereed)
    Abstract [en]

    Experimental determination of the cobalt solubility in the three-phase triangle face-centered cubic + Cr7C3 + graphite have been carried out. In the present work these results are compared with atomistic calculations of the solubility of Co in Cr7C3 phase based on ab initio cohesive energies and lattice inversion method. Comparisons are also made with the literature data reported earlier [Koster W, Sperner F. Arch Eisenhuttenwesen 1955;26:555; Thompson ER, Lemkey FD, Metall Trans 1970-1:2799; Sabin PR, Watts DJ. Metall Trans 1971;2:1260; Sahm PR, Lorenz M, Hugi W, Fruhauf V. Mettal Trans 19723:1022; Tuma H, Lobl K. Kovove Mater 1971;9:221; Fritscher K. Thermochim Acta 1979;29:357].

  • 41.
    Tian, Ye
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Lienert, Ulrich
    Borgenstam, Annika
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Fischer, Torben
    Hedström, Peter
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Martensite formation during incremental cooling of Fe-Cr-Ni alloys: An in-situ bulk X-ray study of the grain-averaged and single-grain behavior2017In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 136, p. 124-127Article in journal (Refereed)
    Abstract [en]

    The formation of martensite (epsilon and alpha') in metastable austenitic Fe-18Cr-(10-11.5)Ni alloys was investigated in situ during cooling. High-energy X-rays were used to study the bulk of the alloys. Both grain-averaged and single grain data was acquired. s played an important role in the formation of a' with an indistinguishable difference in the martensite start temperature. The single-grain data indicated that stacking faults appear as precursors to a An analogy can be made with deformation-induced martensitic transformation, where the generation of nucleation sites would significantly lower the driving force required to overcome the energy barrier in low stacking fault energy Fe-Cr-Ni alloys.

  • 42. Wang, C.
    et al.
    Zhao, Zhe
    Department of Physical Inorganic and Structural Chemistry, Stockholm University.
    Transparent MgAl2O4 ceramic produced by spark plasma sintering2009In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 61, no 2, p. 193-196Article in journal (Refereed)
    Abstract [en]

    A two-step pressure profile was used to prepare transparent MgAl(2)O(4) ceramic without sintering aids by spark plasma sintering (SPS) at 1300 degrees C for 3 min. The influence of the pressure profile was investigated systematically and the discoloration in the present study was attributed to the dislocation formed during the fast densification in SPS. At low pre-load pressure, 5 MPa, with the normal characteristic fast heating rate (100 degrees C min(-1)), high inline transmittance of 51% at 550 nm and 85% at 2000 nm can be achieved.

  • 43.
    Zhao, Guo-Hua
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Tohoku University, Japan.
    Ketov, Sergey V.
    Mao, Huahai
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Borgenstam, Annika
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Louzguine-Luzgin, Dmitri V.
    Ti-Fe-Sn-Nb hypoeutectic alloys with superb yield strength and significant strain-hardening2017In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 135, p. 59-62Article in journal (Refereed)
    Abstract [en]

    In this letter new Ti-Fe-Sn-Nb hypoeutectic alloy comprised of primary dendritic β-Ti and ultrafine (β-Ti + TiFe) eutectic was developed showing superior mechanical properties. The as-cast Ti67Fe27Sn3Nb3 (at.%) alloy exhibited exceptionally high yield stress (2.18 GPa) comparable to that of bulk metallic glasses. Most importantly, the sample presented significant strain-hardening (320 MPa) and enhanced plasticity. The slip deformation and dislocation accumulation in the β-Ti dendrite contribute to the plasticity and the pronounced strain-hardening, whereas the high strength stems from the ultrafine (β-Ti + TiFe) eutectic structure as well as the solution hardening in the multicomponent system.

  • 44.
    Zhou, Jing
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Odqvist, Joakim
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Höglund, Lars
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Thuvander, M.
    Barkar, Thomas
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Hedström, Peter
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Initial clustering - A key factor for phase separation kinetics in Fe-Cr-based alloys2014In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 75, p. 62-65Article in journal (Refereed)
    Abstract [en]

    Clustering of alloying elements in solution-treated Fe-Cr-based alloys is of considerable importance for their microstructure stability upon aging. The clustering of Cr after solution treatment in three stainless steel alloy categories has been studied by atom probe tomography. Furthermore, phase-field simulations are applied to examine the effect of initial clustering on phase separation evolution. It is concluded that the clustering of Cr found in solution-treated ferritic and duplex alloys plays a critical role in the nanostructure evolution during aging.

  • 45.
    Zhou, Jing
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Odqvist, Joakim
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Ågren, John
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Ruban, Andrei
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Multiscale Materials Modelling.
    Thuvander, Mattias
    Xiong, Wei
    Olson, Gregory B.
    Hedström, Peter
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Physical Metallurgy.
    Direct atom probe tomography observations of concentration fluctuations in Fe-Cr solid solution2015In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 98, p. 13-15Article in journal (Refereed)
    Abstract [en]

    The local concentration of atoms in an Fe-46.5 at.% Cr alloy, solution treated at four different temperatures above the miscibility gap, has been investigated using atom probe tomography. It is experimentally found that Cr atoms cluster in the solid solution and that the clustering tendency decreases with increasing temperature above the miscibility gap. These findings are corroborated by Monte Carlo simulations of the atomic short-range order, which show that clustering markedly decrease with increasing temperature from 800 to 1200 degrees C.

  • 46.
    Ågren, John
    KTH, Superseded Departments, Metallurgy.
    On the classification of phase transformations2002In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 46, no 12, p. 893-898Article in journal (Refereed)
    Abstract [en]

    The various classification schemes, based on thermodynamics, microstructure or mechanism, are discussed and criticized from a practical as well as a more fundamental point of view. For example, it is generally not meaningful to consider first and second-order transformations as equivalent with heterogeneous and homogeneous transformations, respectively.

1 - 46 of 46
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf