du.sePublications
Change search
Refine search result
1 - 18 of 18
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • chicago-author-date
  • chicago-note-bibliography
  • 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. Berger, Robert
    et al.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Material Science.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Hörnström, Sven Erik
    A comparative study of the corrosion protective properties of chromium and chromium free passivation methods2007In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 202, no 2, p. 391-397Article in journal (Refereed)
    Abstract [en]

    Commercially available passivation methods for white-rust protection of hot-dip galvanized steel have been investigated. The passivations were either based on trivalent chromium or chromium free. A chromate based conversion coating was used for reference. The treated panels were tested with regard to white rust protection and paintability. The surface chemistry of the conversion coatings was monitored with scanning Auger electron spectroscopy and X-ray photoelectron spectroscopy. Coating thicknesses were measured using Auger electron sputter depth profiling. The passivations were applied with a thickness recommended by the supplier and thus showed large variation. The thickness of the chromium free passivation (Cr-free) is approximately 75 nm. The coating contains the active ions; H3O+, Ti4+, Mn2+, Zn2+, PO4 3-. The passivation based on trivalent chromium (Cr-III) is approximately 30 nm thick and contains the active ions; H3O+ Cr3+, PO4 3-, F. The chromate based passivation (Cr- VI) is approximately 5 nm thick and contains the active ions Cr6+/Cr3+, F-. The Cr-free and the Cr-III passivations showed similar white rust protection in the corrosion tests. The corrosion resistance was good although it did not fully reach the level of the Cr-VI passivation. The results from the tests of the painted panels showed that the powder paint worked well on all three passivations. The solvent born paint worked best on the passivation based on trivalent chromium. The water born paint showed poor resistance to blistering in the Cleveland humidity test for all three passivations. In this test the passivation with hexavalent chromium showed slightly better results than the chromate free passivations.

  • 2.
    Berger, Robert
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Material Science.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Hörnström, Sven Erik
    Properties of Chromate Free Passivations for Hot-Dip Galvanized Steel2006In: CORROSION/2006, San Diego, California, USA, 2006Conference paper (Other academic)
  • 3.
    Berger, Robert
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Material Science.
    Stavlid, N.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    The influence of alkali-degreasing on the chemical composition of hot-dip galvanized steel surfaces2006In: Surface and Interface Analysis, ISSN 0142-2421, E-ISSN 1096-9918, Vol. 38, no 7, p. 1130-1138Article in journal (Refereed)
    Abstract [en]

    The influence of dipping temperature and time on the surface chemistry of hot-dipped galvanized steel sheets during the alkaline degreasing process is investigated. The surface chemistry was monitored with scanning Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). The results show high Al concentrations on the untreated surfaces, which are significantly reduced during alkaline degreasing. The same conclusions could be drawn for the carbon compounds that accumulate on the surface during storage. The measurements reveal a gradual reduction in surface Al as the alkali solution temperature and/or degreasing time are increased. When degreasing was conducted at 70 °C for 30 s the surface was practically free from Al, which was present only in small islands. Furthermore, the experiments showed that the thickness of the oxide film covering the surfaces before and after alkaline degreasing is approximately 20 Å. The main constituents of the film varied from ZnAl hydroxide/oxide to Zn hydroxide/oxide, before and after degreasing, respectively. 

  • 4.
    Bexell, Ulf
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Berger, Robert
    Dalarna University, School of Technology and Business Studies, Material Science.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Sundell, Per-Erik
    Johansson, Mats
    Bonding of vegetable oils to mercapto silane treated metal surfaces: surface engineering on the nano scale2006In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 515, no 2, p. 838-841Article in journal (Refereed)
    Abstract [en]

    In this paper the bonding of thin vegetable oil films on mercapto silane treated aluminium surfaces has been studied. The silane molecules are attached to the surface by metal–oxygen–silicon bonds. The coupling between the unsaturated bonds of the vegetable oil and the thiol functionalised surface was obtained through a photoinduced thiol-ene reaction. The surfaces were characterised by X-ray photoelectron spectroscopy (XPS). Vegetable oil contains both saturated and unsaturated carbon chains. For the reactions investigated in this study it is the unsaturated carbon chains that can react by a thiol-ene reaction and the results indicate that it is possible to attach a vegetable oil to a metal surface pre-treated with a thiol functionalised silane.

  • 5.
    Bexell, Ulf
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    A corrosion study of hot-dip galvanized steel sheet pre-treated with gamma-mercaptopropyltrimethoxysilane2007In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 201, no 8, p. 4734-4742Article in journal (Refereed)
    Abstract [en]

    In the present work an organofunctional silane, gamma-mercaptopropyltrimethoxysilane (gamma-MPS), has been deposited on hot-dip galvanized cold rolled steel from different silane solution concentrations. Painted and unpainted silane treated samples were corrosion tested and painted samples were adhesion tested. The surface chemistry of the unpainted silane treated samples was investigated with AES, ToF-SIMS and EDS and the surface morphology was studied with SEM. The results show that the silane film thickness is dependent on the silane concentration in the silane solution and a higher silane concentration gives a thicker film. Moreover, thicker films tend to give films with a pronounced crack pattern and even detachment of film debris. Corrosion tests of unpainted samples show that gamma-MPS can not work as a passivation treatment but gives a very good adhesion to the paint

  • 6.
    Bexell, Ulf
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Gelius, Ulrik
    XPS and AES Characterisation of hydrolysed ?- Mercaptopropyltrimethoxysilane deposited on Al, Zn and Al-43.4Zn-1.6Si alloy coated steel2004In: Surface and Interface Analysis, ISSN 0142-2421, E-ISSN 1096-9918, no 36, p. 624-631Article in journal (Refereed)
  • 7. Birgerson, J.
    et al.
    Lindsjö, A.
    Selo Mustafa, Muhammed
    Dalarna University, School of Technology and Business Studies, Material Science.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Skarp, Kent
    Dalarna University, School of Technology and Business Studies, Material Science.
    Spectroscopic study of chemically stabilized dichroic thin crystal films2004In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 236Article in journal (Refereed)
  • 8.
    Birgerson, Jonas
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Lindsjö, A
    Selo Mustafa, Muhammed
    Dalarna University, School of Technology and Business Studies, Material Science.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Skarp, Kent
    Dalarna University, School of Technology and Business Studies, Material Science.
    Spectroscopic study of chemically stabilized dichroic thin crystal films2004In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, no 236, p. 444-450Article in journal (Refereed)
  • 9.
    Engkvist, Josefin
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Material Science.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    High temperature oxidation of FeCrAl-alloys: influence of Al-concentration on oxide layer characteristics2009In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 60, no 11, p. 876-881Article in journal (Refereed)
    Abstract [en]

    The superior high temperature oxidation resistance of FeCrAl alloys relies on the formation of a dense and continuous protective aluminium oxide layer on the alloy surface when exposed to high temperatures. Consequently, the aluminium content, i.e. the aluminium concentration at the alloy–oxide layer interface, must exceed a critical level in order to form a protective alumina layer. In the present study the oxidation behaviour of six different FeCrAl alloys with Al concentrations in the range of 1.2–5.0wt% have been characterised after oxidation at 900 8C for 72 h with respect to oxide layer surface morphology, thickness and composition using scanning electron microscopy, energy dispersive X-ray spectroscopy and Auger electron spectroscopy.The results show that a minimum of 3.2wt% Al in the FeCrAl alloy is necessary for the formation of a continuous alumina layer. For Al concentrations in the range of 2.0–3.0wt% a three-layered oxide layer is formed, i.e. an oxide layer consisting of an inner alumina-based layer, an intermediate chromia-based layer and an outer iron oxide-based layer. In contrast, the 1.2wt% Al FeCrAl alloy is not able to form a protective oxide layer inhibiting extensive oxidation.

  • 10.
    Engkvist, Josefin
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Material Science.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    ToF-SIMS Analysis of a FeCrAl Alumina Forming Alloy2004In: SIMS Europe 2004, Münster, Germany, 2004Conference paper (Other academic)
  • 11.
    Engkvist, Josefin
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Material Science.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    ToF-SIMS Depth Profiling of Alumnia Formed on a FeCrAl High Temperature Alloy2003In: Proceedings of the 14th International Conference on Secondary Ion Mass Spectrometry, San Diego, California, USA, 2003Conference paper (Refereed)
  • 12.
    Engkvist, Josefin
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Material Science.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Early stages of oxidation of uncoated and PVD SiO2 coated FeCrAl foils2009In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 203, no 19, p. 2845-2850Article in journal (Refereed)
    Abstract [en]

    The high temperature oxidation characteristics of uncoated and SiO2 PVD-coated FeCrAl foils have been investigated when exposed to laboratory air at 1000 °C during 1, 2, 4, 8, 16, 32 and 60 min. The oxidized samples were characterized using SEM, EDS, AES and SIMS. The results show that the presence of a 100 nm thin SiO2 PVD coating significantly reduces the oxidation rate of the FeCrAl foil during early stages of oxidation. The decreased oxidation rate displayed by the SiO2 coated FeCrAl foil is the result of the SiO2 coating acting as an initial diffusion barrier promoting the formation of a predominantly inward growing Al2O3 layer during oxidation. Additionally, by using EDS analysis together with AES and SIMS depth profiling it was shown that the total concentration of Si in the grown oxide scale decreased during oxidation.

  • 13.
    Fallqvist, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Ruppi, S
    Seco Tools.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Ottosson, M
    Uppsala Universitet.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology. Sandvik Materials Technology.
    Nucleation and growth of CVD α-Al2O3on TixOy template2012In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 207, p. 254-261Article in journal (Refereed)
    Abstract [en]

    The microstructure, phase and chemical composition of TixOy templates used to nucleate α-Al2O3 on Ti(C,N) coated cemented carbide have been elucidated using scanning electron microscopy, X-ray diffraction, Auger electron spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry. Further, the adhesive strength of the α-Al2O3–TixOy–Ti(C,N) interfaces was investigated using scratch adhesion testing.

    The present study confirmed that the as-deposited template consisted of a Ti4O7 phase which during subsequent deposition of the Al2O3 layer transformed to a Ti3O5 phase and that the grown Al2O3 layer consisted of 100% α-Al2O3. Furthermore, the results showed that the lowest interfacial strength within the multilayer structure was exhibited by the Ti(C,N)–TixOy interface and that the transformation of Ti4O7 to Ti3O5 in the template resulted in formation of pores in the Ti(C,N)-template interface lowering the interfacial strength even more. The use of surface analysis techniques such as Auger electron spectroscopy and especially Time-of-Flight Secondary Ion Mass Spectrometry enabled trace element analyses using depth profiling to characterise the thin interfacial layers in detail.

  • 14.
    Grehk, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Berger, Robert
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Material Science.
    Investigation of the drying process of linseed oil using FTIR and ToF-SIMS2008In: Proceedings of the 17th International Vacuum Congress/13th International Conference on Surface Science/Internatinal Conference on Nanoscience and Technology, Stockholm, 2008, Vol. 100Conference paper (Refereed)
    Abstract [en]

    The drying process of linseed oil, oxidized at 80 oC, has been investigated with rheology measurements, Fourier transformation infrared spectroscopy (FTIR), and time of flight secondary ion mass spectrometry (ToF-SIMS). The drying process can be divided into three main steps: initiation, propagation and termination. ToF-SIMS spectra show that the oxidation is initiated at the linolenic (three double bonds) and linoleic fatty acids (two double bonds). ToF-SIMS spectra reveal peaks that can be assigned to ketones, alcohols and hydroperoxides. In this article it is shown that FTIR in combination with ToF-SIMS are well suited tools for investigations of various fatty acid components and reaction products of linseed oil.

  • 15.
    Grehk, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Engkvist, Josefin
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Material Science.
    Richter, Jan H
    Karlsson, Patrik G
    Sandell, Anders
    Initial stages of metal-organic chemical-vapor deposition of ZrO2 on a FeCrAl alloy2007In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 516, no 6, p. 875-879Article in journal (Refereed)
    Abstract [en]

    The initial stages of metal-organic chemical-vapor deposition of ZrO2 on a model FeCrAl alloy was investigated using synchrotron radiation photoelectron spectroscopy, X-ray absorption spectroscopy, scanning Auger microprobe, and time of flight secondary mass spectrometry. The coatings were grown in ultra-high vacuum at 400 °C and 800 °C using the single source precursor zirconium tetra-tert-butoxide. At 400 °C the coatings mainly consist of tetragonal ZrO2 and at 800 °C amixed ZrO2/Al2O3 layer is formed. The Almetal diffuses from the FeCrAl bulk to themetal/coating interface at 400 °C and to the surface of the coating at 800 °C. The result indicates that the reactionmechanism of the growth process is different at the two investigated temperatures.

  • 16.
    Grehk, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Göthelid, Mats
    Björkqvist, Magnus
    Le Lay, Guy
    Karlsson, Ulf
    Li-induced phase transition from the Ge(111)3x1:Li surface reconstruction to the Ge(111)rot3xrot3:Li lithium germanid2000In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 61, no 7, p. 4963-4967Article in journal (Refereed)
    Abstract [en]

    We have investigated the Li-induced phase transition from the Ge(111)3×1:Li to the Ge(111)sqrt[3]×sqrt[3]:Li reconstruction with photoemission. The Ge(111)3×1:Li reconstruction can be described as parallel rows of Ge atoms separated by single rows of Li atoms. The Ge(111)sqrt[3]×sqrt[3]:Li reconstruction, on the other hands, has to be described in terms of a Li-germanide phase extending over at least two atomic layers.

  • 17. Karlsson, P. G.
    et al.
    Richter, J. H.
    Blomquist, J.
    Uvdal, P.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Sandell, A.
    Metal organic chemical vapor deposition of ultrathin ZrO2 films on Si(1 0 0) and Si(1 1 1) studied by electron spectroscopy2007In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 601, no 4, p. 1008-1018Article in journal (Refereed)
    Abstract [en]

    The growth of ultrathin ZrO2 films on Si(100)-(2x1) and Si(111)-(7x7) has been studied with core level photoelectron spectroscopy and X-ray absorption spectroscopy. The films were deposited sequentially by chemical vapor deposition in ultra-high vacuum using zirconium tetra-tert-butoxide as precursor. Deposition of a > 50Å thick film leads in both cases to tetragonal ZrO2 (t-ZrO2), whereas significant differences are found for thinner films. On Si(111)-(7x7) the local structure of t-ZrO2 is not observed until a film thickness of 51Å is reached. On Si(100)-(2x1) the local geometric structure of t-ZrO2 is formed already at a film thickness of 11Å. The higher tendency for the formation of t-ZrO2 on Si(100) is discussed in terms of Zr–O valence electron matching to the number of dangling bonds per surface Si atom. The Zr–O hybridization within the ZrO2 unit depends furthermore on the chemical composition of the surrounding. The precursor t-butoxy ligands undergo efficient C–O scission on Si(100), leaving carbonaceous fragments embedded in the interfacial layer. In contrast, after small deposits on Si(111) stable t-butoxy groups are found. These are consumed upon further deposition. Stable methyl and, possibly, also hydroxyl groups are found on both surfaces within a wide film thickness range.

  • 18. Sandell, A.
    et al.
    Karlsson, P. G.
    Richter, J. H.
    Blomquist, J.
    Uvdal, P.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Growth of ultrathin ZrO2 films on Si(100): film-thickness-dependent band alignment2007In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 88, no 13, article id 132905Article in journal (Refereed)
    Abstract [en]

    The band alignment of ultrathin ZrO2 films of different thickness formed on Si(100) have been monitored with synchrotron radiation photoelectron spectroscopy and x-ray absorption spectroscopy. The films were deposited sequentially by way of metal-organic chemical-vapor deposition in ultrahigh vacuum. A significant decrease in the conduction band offset is found for increasing film thickness. It is accompanied by a corresponding increase of the valence band offset. The variations originate in the formation of an interfacial layer characterized by a lower degree of Zr-O interaction than in bulk ZrO2 but with no clear evidence for partially occupied Zr 4d dangling bonds.

1 - 18 of 18
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • chicago-author-date
  • chicago-note-bibliography
  • 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