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  • 101.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Tribological evaluation of some potential tribo materials used in column lift rolling contacts: a case study2011In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 270, no 9-10, p. 720-724Article in journal (Refereed)
    Abstract [en]

    The friction and wear characteristics of some potential tribological pairs aimed for the wheel/rail rolling contact in column lifts were studied. Tribo tests were performed using a pin-on-disc equipment and the tribological pairs included; stainless steel against ball bearing steel, stainless steel against WC/C-coated ball bearing steel and stainless steel against cast nylon (polyamide 6). The influence of coating surface topography as well as stainless steel surface topography on the friction and wear behaviour of the tribological pairs was investigated. The results show that the WC/C-coating significantly improves the tribological performance of the stainless steel/ball bearing steel sliding couples but that the WC/C-coating show a limited life-time in sliding contact with stainless steel under the prevailing contact conditions. In contrast, the stainless steel/ball bearing steel sliding couples suffer from high friction and wear due to strong adhesion between the mating surfaces followed by metal transfer and severe adhesive wear. The stainless steel/cast nylon sliding couples show a somewhat intermediate behaviour regarding friction and wear where the friction is controlled by the generation of a polymer transfer film and wear of the cast nylon is controlled by the surface topography of the mating stainless steel surface. The results obtained are discussed in relation to the identified friction and wear mechanisms as characterized by SEM and EDX.

  • 102.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Tråddragningens tribologi2015In: Nordisk Trådteknisk Förening: Årsbok 2015 / [ed] Leif Eriksson, NTTF , 2015Chapter in book (Other academic)
  • 103.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Wear resistant materials in mining, drilling and rock handling2014Conference paper (Other academic)
  • 104.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Friction characteristics and material transfer tendency in metal powder compaction2011In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 271, no 9-10, p. 1903-1908Article in journal (Refereed)
    Abstract [en]

    The friction characteristics and material transfer tendency between metal powder and die tool material in metal powder compaction play an important role in the production of near-net-shape components of high density. A natural step to further increase the green density and simplify the sintering process is to reduce the amount of internal lubricant in the powder since the volume fraction of an organic lubricant will result in a significant contribution to the resulting porosity. However, this will significantly increase the adhesive contact and thus the friction between the die and the powder/green body during the powder compaction process. As a result, the compaction and ejection forces as well as the wear rate of the die and punch surfaces will increase. Consequently, improved knowledge concerning the friction mechanisms prevailing at the metal powder/die tool material interface is needed. The present paper will present data regarding the influence of type of tool and coating material on the friction characteristics and material transfer tendency during simulated powder compaction of a water atomized plain iron powder under no or starved lubrication conditions using two different laboratory tribo tests. Tool materials investigated include ingot cast tool steel, powder metallurgy (PM) tool steel and TiAlN and DLC-type PVD coatings. Post-test characterization using scanning electron microscopy and energy dispersive X-ray spectroscopy was used to analyse the tribo surfaces and especially the tendency to material transfer and tribo film formation. The results show that the material transfer tendency is mainly controlled by strong adhesive metal–metal contacts and that a PVD coating showing intrinsic low-friction properties and a smooth surface topography may significantly reduce the interaction between the mating surfaces promoting a stable friction and a low material transfer tendency.

  • 105.
    Olsson, Mikael
    et al.
    Dalarna University, School of Information and Engineering, Materials Technology.
    Cinca, Nuria
    Mechanisms controlling friction and material transfer in sliding contacts between cemented carbide and aluminum during metal forming2024In: International journal of refractory metals & hard materials, ISSN 0263-4368, Vol. 118, article id 106481Article in journal (Refereed)
    Abstract [en]

    Cold forming of aluminum alloys is frequently associated with problems related to severe adhesion and material transfer onto the forming tools which results in high friction forces and negatively affects the surface quality of the formed parts, a phenomenon frequently named galling. In the present study, well controlled laboratory tests using a scratch testing equipment have been performed to evaluate the friction characteristics and investigate the mechanisms controlling the initial transfer of aluminum in dry sliding contact with five different cemented carbide grades. In the tests, an aluminum pin (representing the work material) with a conical tip slides against a flat, fine-polished, cemented carbide surface (representing the tool). During sliding, the mechanical contact results in plastic deformation and flattening of the work material against the tool surface, thus simulating a metal forming contact. The small scale and well-defined tribo contact in combination with post-test surface characterization using optical surface profilometry, high resolution SEM and EDS makes it possible to evaluate the influence of material transfer on the friction characteristics.The results show that sub-mu m surface irregularities in the cemented carbide surface trigger mechanical interaction with the softer aluminum surface which promotes aluminum transfer to the cemented carbide surface resulting in high friction. Common surface irregularities, promoting aluminum transfer, are sharp edges of slightly protruding carbide grains, surface steps in connection to binder phase pockets, surface steps in connection to surface pores, etc. It should be noted that even very small surface steps, < 20 nm in height, constitute efficient cutting edges able to effectively cut off the passing aluminum material and thus have a very strong impact on material transfer. In contrast, the effect of carbide composition, e.g. the presence of cubic carbides of different composition, seems to be of minor importance to reduce the adhesion and the tendency to material transfer.

  • 106.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Heinrichs, J
    Uppsala Universitet.
    Yvell, Karin
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Jacobson, S
    Uppsala Universitet.
    On the relevance of hardness as a material parameter in the deformation and wear of  cemented carbides in rock drilling2014Conference paper (Refereed)
  • 107.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Heinrichs, J
    Uppsala Universitet.
    Yvell, Karin
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Jacobson, S
    Uppsala Universitet.
    Towards a better understanding of the wear of cemented carbide drill bit inserts in rock drilling2014Conference paper (Other academic)
  • 108.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Heinrichs, Jannica
    Yvell, Karin
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Jacobson, Staffan
    Initial degradation of cemented carbides for rock drilling: model studies of the tribological contact against rock2015In: International journal of refractory metals & hard materials, ISSN 0263-4368, Vol. 52, p. 104-113Article in journal (Refereed)
    Abstract [en]

    Hardness and fracture toughness are often used as the prime material parameters to characterise cemented carbides used in rock drilling. However, the deformation and wear of cemented carbide are too complicated to be described by these parameters alone. The cemented carbide and the wearing rock mineral are both composite materials, containing phases with widely varying hardness. Moreover, the deformation behaviour of the individual phases may be strongly anisotropic, as for the WC grains in the cemented carbide. The wear of the cemented carbide typically occurs on the scale of individual grains or smaller. Contrastingly, the hardness stated for both is typically a macroscopic value, averaged over numerous grains, orientations, etc. The present investigation aims to contribute to the understanding of the relations between microstructure, properties and wear mechanisms of cemented carbide buttons in rock drilling. It is focused on the role of scale of deformation in relation to size of the different phases of the cemented carbide. This is achieved by simplifying the contact situation of the rock drill button to a single stylus sliding contact between a granite stylus and a polished cemented carbide surface. The deformation and wear of this well controlled contact is then evaluated on the sub-micrometer scale; using high resolution FEG-SEM with EBSD, FIB cross-sectioning and AFM. The results show that even an extremely local deformation, such as slip within individual WC grains, affects the tribological contact, and that the nominally much softer granite may cause deformation both within individual WC grains, and on the composite scale. The results are discussed with respect to their significance for wear of cemented carbides in rock drilling. (C) 2015 Elsevier Ltd. All rights reserved.

  • 109.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Hogmark, Sture
    Wear mechanisms of HSS cutting tools2008In: Gear Solutions, ISSN 1933 - 7507, Vol. June, p. 20-29Article in journal (Refereed)
  • 110.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Högman, B
    Uddeholms.
    Influence of tool steel microstructure on the prevailing wear mechanisms in metal powder compaction2012In: TOOL 2012 : proceedings of the 9th international tooling conference, developing the world of tooling, Montanuniversität Leoben 11-14 September 2012 / [ed] Herald Leitner, Regina Kranz, Angelika Tremmel, Knittelfeld: Gutenberghaus , 2012, p. 409-416Conference paper (Refereed)
  • 111.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Karlsson, P.
    Eriksson, Jenny
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Gåård, A.
    Krakhmalev, P.
    Bergström, J.
    Galling resistance evaluation of tool steels by two different laboratory test methods for sheet metal forming2011In: Proceedings of the 18th International Conference on Wear of Materials, Philadelphia, USA, 2011Conference paper (Other academic)
  • 112.
    Olsson, Mikael
    et al.
    Dalarna University, School of Information and Engineering, Materials Technology.
    Lundin, Peter
    Swerim.
    Samuelsson, Jan-Erik
    Erasteel Kloster.
    Tjerngren, Peter
    SMT/Alleima.
    Åhlberg, Richard
    Fagersta Stainless.
    Börjesson, Malin
    Kanthal.
    Balazs, Emil
    Ovako.
    Färre ytfel på varmvalsade produkter2022Report (Other academic)
  • 113.
    Olsson, Mikael
    et al.
    Dalarna University, School of Information and Engineering, Materials Technology.
    Lundin, Peter
    Swerim.
    Samuelsson, Jan-Erik
    Erasteel Kloster.
    Tjerngren, Peter
    SMT/Alleima.
    Åhlberg, Richard
    Fagersta Stainless.
    Börjesson, Malin
    Kanthal.
    Balazs, Emil
    Ovako.
    YTFEL Deelrapport - Verksförsök2022Report (Other academic)
  • 114.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Malmros, M.
    Bexell, Ulf
    Wiklund, U.
    Assessing the mechanical and electrical properties of aluminium oxid on aluminium using nanoindentation and nonoscratching2011In: Proccedings of the 18th International Conference on Wear of Materials, Philadelphia, USA, 2011Conference paper (Other academic)
  • 115.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Sandberg, Odd
    Tribological evaluation of tool materials for powder compaction2010In: Proceedings of the World Powder Metallurgy Congress and Exhibition, World PM 2010, Florence, 2010, Vol. 5Conference paper (Refereed)
    Abstract [en]

    The friction characteristics and material transfer tendency between metal powder and tool material in metal powder compaction have been evaluated using a new tribo test method. The method is based on controlled scratch testing using a commercial scratch tester but instead of the commonly used Rockwell C diamond stylus a sample holder with a small green body of compacted powder particles is drawn over the surface in a well controlled multi pass linear reciprocating sliding contact. In the present study a number of combinations of metal powder and tool materials have been evaluated with respect to the friction characteristics and the sticking and cladding tendency at the sliding interface. Post test scanning electron microscopy and energy dispersive X-ray spectroscopy in combination with 3D white light interferometry were used to analyse the tool material surfaces and material pick-up tendency. The tribological performance of potential powder compacting tool materials is discussed in relation to the identified friction and wear mechanisms.

  • 116.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Surreddi, Kumar Babu
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Scratch testing of cemented carbides - Influence of Co binder phase and WC grain size on surface deformation and degradation mechanisms2018In: Proceedings of The 18th Nordic Symposium on Tribology - Nordtrib 2018 / [ed] Staffan Jacobson, Uppsala: Uppsala University, 2018Conference paper (Refereed)
    Abstract [en]

    In the present study, the microstructural response of some commercial cemented carbide grades during scratchinghas been analyzed and evaluated by a number of post-test characterization techniques. The influence of Co binder phase content and WC grain size on the deformation and degradation on a WC grain size scale and on a composite scaleare evaluated. The results clearly illustrate the complexity of deformation, degradation and wear of cemented carbide and the dynamics of the diamond stylus / cemented carbide contact during the scratching event. For all cementedcarbide grades the microstructure has a strong impact on the observed degradation mechanisms and the resistance to deformation and degradation was found to increase with decreasing Co content and decreasing WC grain size.

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  • 117.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Surreddi, Kumar Babu
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Thin hard CVD and PVD coatings and their potential in steel wire drawing applications2018In: Proceedings of The 18th Nordic Symposium on Tribology - NORDTRIB 2018 / [ed] Staffan Jacobson, Uppsala: Uppsala University, 2018Conference paper (Refereed)
    Abstract [en]

    In the present work, the potential of using thin hard CVD and PVD coatings in order to improve the performance of cemented carbide steel wire drawing nibs is evaluated. Coating materials include some state-of-the-art CVD and PVD coatings and pre- and post-coating treatments were used to improve the surface topography of the coated functional surfaces. The tribological performance of the coatings has been evaluated by sliding wear tests and wire drawing experiments under well controlled conditions. Post-test characterization of the coated nibs using 3D optical surface profilometry, scanning electron microscopy and energy dispersive X-ray spectroscopy illustrates the pros and cons of the two deposition techniques but also that the coatings have a potential to improve the performance of cemented carbide nibs in steel wire drawing applications.

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    fulltext
  • 118.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Material Science.
    Wadman, B.
    Eriksson, Jenny
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Schedin, E.
    Madsen, E.
    Bay, N.
    Influence of stainless steel surface texture on galling2011In: Proceedings of the 18th International Conference on Wear of Materials, Philadelphia, USA, 2011Conference paper (Other academic)
  • 119.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. Ångström Tribomaterials Group, Uppsala University.
    Yvell, Karin
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Heinrichs, J.
    Bengtsson, M.
    Jacobson, S.
    Surface degradation mechanisms of cemented carbide drill buttons in iron ore rock drilling2017In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 388-389, p. 81-92Article in journal (Refereed)
    Abstract [en]

    The wear behavior of cemented carbide rock drill buttons is influenced by many factors, which include the composition and microstructure of the cemented carbide material, the nature of the rock material, and the conditions of the rock drilling operation. Depending on the type of rock and on the drilling procedure used, the cemented carbide is exposed to substantially differing mechanical and thermal conditions. In the present study, the surface degradation and wear mechanisms of cemented carbide drill buttons exposed to iron ore rock drilling have been characterized based on a combination of high resolution scanning electron microscopy (SEM), focused ion beam cross-sectioning (FIB), energy-dispersive X-ray spectroscopy (EDS) and electron back scatter diffraction (EBSD).The results show a significant difference in surface degradation and wear between the front and peripheral buttons of the drill bits. While the front buttons display a relatively smooth worn surface with shallow surface craters the peripheral buttons display a reptile skin pattern, i.e. plateaus, 200-300. μm in diameter, separated by valleys, typically 40-50. μm wide and 15-30. μm deep, The reptile skin pattern is obtained in regions where the peripheral buttons are in sliding contact against the drill hole walls and exposed to high surface temperatures caused by the frictional heating. The results indicate that the reptile skin pattern is related to friction induced thermal stresses rather than mechanical contact stresses, i.e. the reptile skin pattern is formed due to thermal fatigue, rather than mechanical fatigue, caused by the cyclic frictional heating generated at the cemented carbide button/iron ore interface.

  • 120.
    Olsson, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Yvell, Karin
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Heinrichs, Jannica
    Uppsala University.
    Bengtsson, Maria
    LKAB Wassara AB.
    Jacobson, Staffan
    Uppsala University.
    Surface degradation mechanisms of cemented carbide drill buttons exposed to iron ore rock drilling2016In: Proceedings of the 17th Nordic Symposium on Tribology - Nordtrib 2016, 2016Conference paper (Refereed)
    Abstract [en]

    The wear behavior of cemented carbide rock drill buttons is influenced by many factors, which include the composition and microstructure of the cemented carbide material, plus the conditions of the rock drilling operation, such as drilling parameters, drill button geometry and the nature of the rock material. Depending on the type of rock and on the drilling procedure used, the cemented carbide is exposed to substantially differing mechanical and thermal conditions. Under conditions of high mechanical stress and high temperatures, typical for drilling in highly abrasive rocks such as granite, the worn cemented carbide buttons are usually very smooth, with the roughness limited to within the size of individual WC grains. When drilling under conditions of moderate mechanical stress and high temperatures, typical for drilling in low-abrasive rock, such as ores with e.g. magnetite, the surface damage of the buttons usually includes a macroscopic surface wear pattern, commonly referred to as “reptile skin”, in an otherwise smooth surface. The crack growth associated to the valleys of the reptile skin pattern eventually leads to catastrophic fracture of the button, unless the cracked surface layer is repeatedly ground off before the cracks grow too deep. So despite the low general wear rate, the wear life of drill buttons becomes severely restricted by the surface cracks. The present study focuses on revealing the degradation mechanisms behind the formation of the reptile skin. This is done by analyzing drill buttons exposed to different stages of degradation and wear from drilling in iron ore. The work is based on a combination of high resolution scanning electron microscopy (SEM), focused ion beam microscopy (FIB), energy-dispersive X-ray spectroscopy (EDS) and electron back scatter diffraction (EBSD).

  • 121.
    Olsson, Mikael
    et al.
    Dalarna University, School of Information and Engineering, Materials Technology.
    Åhlberg, Richard
    Fagersta Stainless.
    YTFEL Delrapport - Ytfelsatlas2022Report (Other academic)
  • 122.
    Pejryd, Lars
    et al.
    Örebro University.
    Larsson, Joakim
    Örebro University.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Process monitoring of wire drawing using vibration sensoring2017In: CIRP - Journal of Manufacturing Science and Technology, ISSN 1755-5817, E-ISSN 1878-0016, Vol. 18, p. 65-74Article in journal (Refereed)
    Abstract [en]

    Automating the detection of processing conditions that may lead to defects in the wire during the wire drawing process is of high interest to the industry. Current practise is based primarily on operator experience. Increasing demands on product quality and process robustness emphasises the need for development of robust in-process detection methods. This work is focusing on investigating the potential of using vibration monitoring to detect process deficiencies or variations that may lead to defects in the product. Wire drawing of a carbon steel in different lubricating situations was used to investigate vibration signal response together with force measurements and surface investigation of the wire product. The results show that vibration measurement is capable of detecting loss of lubrication that leads to poor surface quality of the wire.

  • 123. Prosek, T.
    et al.
    Thierry, D.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Material Science.
    Effects of chloride-to-chromate ratio on the protective action of zinc surface films under atmospheric weathering conditions2007In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 63, no 3, p. 258-267Article in journal (Refereed)
    Abstract [en]

    The formation and the corrosion protection of newly formed chromium-rich layers on bare zinc surfaces were studied to model the conditions in defected areas of both organic and conversion chromate coatings that are in contact with water environments contaminated with different amounts of chloride ions. Composition of the layers was idenified with Fourier transformed infrared spectroscopy (FTIR), x-ray absorption near-edge structure (XANES), and secondary ion mass spectroscopy (SIMS). The presence of chloride in the range from 0.06 mM to 1, 000 mM in the chromate treating solution had almost no effect on the amount of chromate adsorbed on zinc. Three independent techniques showed that a more than 4-order increase in chloride concentration results in the drop of the chromate content in the surface film only by 20% to 25%. Cr(VI)-to-total Cr surface ratio was close to 0.3 and constant under present experimental conditions. More chromium was detected in the outer region of the film, whereas chloride accumulated in the inner region. As a result of the linear increase of the surface chloride concentration with the chloride concentration in the chromate treating solution, the chloride-to-chromate surface molar ratio increased sharply. The rate of reduction of Cr(VI) to Cr(III) and the corrosion rate of zinc exposed to atmospheric weathering conditions increased significantly with the chloride-to-chromate ratio. The chromate coatings showed good stability and a high level of corrosion protection, up to the ratio of approximately 2. It represented a threshold value below which relatively low rates of the chromate reduction and zinc corrosion were observed, since the significant part of the chloride ions was inactivated in the first hours of exposure by the formation of insoluble corrosion products. A negative effect of the increasing chloride-to-chromate surface molar ratio on corrosion can be seen in the increasing ability to reduce oxygen on the zinc surface measured by the scanning Kelvin probe (SKP) technique. Inhibition of the cathodic reaction by chromate was less effective at higher ratios.

  • 124. Rendon, José
    et al.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Abrasive wear resistance of some commercial abrasion resistant steels evaluated by laboratory test methods2009In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 267, no 11, p. 2055-2061Article in journal (Refereed)
    Abstract [en]

    The aim of the present study is to evaluate the abrasive wear resistance of some potential abrasion resistant steels exposed to different types of abrasive wear contact conditions typical of mining and transportation applications. The steels investigated, include a ferritic stainless steel, a medium alloyed ferritic carbon steel and a medium alloyed martensitic carbon steel. The abrasive wear resistance of the steels was evaluated using two different laboratory test methods, i.e. pin-on-disc testing and paddle wear testing that expose the materials to sliding abrasion and impact abrasion, respectively. All tests were performed under dry conditions in air at room temperature. In order to evaluate the tribological response of the different steels post-test characterization of the worn surfaces were performed using optical surface profilometry, scanning electron microscopy and energy dispersive X-ray spectroscopy. Besides, characterization of the wear induced sub-surface microstructure was performed using optical microscopy. The results show that depending on the abrasive conditions a combination of high hardness and toughness (fracture strain) is of importance in order to obtain a high wear resistance. In the pin-on-disc test (i.e. in sliding abrasion) these properties seem to be controlled by the as-rolled microstructure of the steels although a thin triboinduced sub-surface layer (5-10 mu m in thickness) may influence the results. In contrast, in the paddle wear test (i.e. in impact abrasion), resulting in higher forces acting perpendicular to the surface by impacting stones, these properties are definitely controlled by the properties of the active sub-surface layer which also contains small imbedded stone fragments.

  • 125. Roizard, X.
    et al.
    Heinrichs, J.
    Et Taouil, A.
    Jacobson, S.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Melot, J. M.
    Lallemand, F.
    Insights into sliding wear and friction behavior of copper in ethanol containing alkylphosphonic acid molecules2016In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 96, p. 141-148Article in journal (Refereed)
    Abstract [en]

    In this work, the friction and wear behavior of bare copper was investigated for the first time under lubricated sliding conditions in diluted ethanol solutions of butylhosphonic (C4P), octylphosphonic (C8P), dodecylphosphonic (C12P), and hexadecylphosphonic (C16P) acids. The technique aims towards a more environmentally friendly lubrication to be used in shaping of copper sheets. Bare copper samples were subjected to unidirectional sliding using a tribometer with ball-on-disk contact geometry. Copper substrates (20 mm2×1 mm) were run against 100Cr6 ∅10 mm ball bearing counterbodies. All tests were conducted using the same sliding conditions with a normal load of 10 N, tangential velocity of 0.01 m/s, at room temperature of 20 °C. Worn surfaces were analyzed by Scanning Electron Microscopy, Optical Microscopy and White Light Interference Profilometry. When comparing to sliding tests in the pure ethanol solvent, significant decreases in terms of wear track dimensions, transferred material on the ball and friction coefficients are observed when active molecules are present in the solution. These form protective tribofilms exhibiting lubricating and anti-wear properties. Deeper studies on the tribological behavior of copper in C4P solution show that both low friction and low transfer of work material to the ball prevail in a specific range of low molecule concentration (5×10-4 M; 25×10-4 M). Even if the molecules are introduced during the test, after a few cycles, the tribological behavior improves, regardless of both friction level and copper surface degradation. Finally, specific friction tests were performed to further investigate the mechanisms. It was found that two mechanisms are involved; firstly molecules grafting onto the surface directly reduces friction, and secondly transformation of these grafted molecules into a tribofilm during the first mechanical contact cycles reduces it even further. 

  • 126.
    Safara Nosar, Nima
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Influence of tool steel surface topography on adhesion and material transfer in stainless steel/tool steel sliding contact2013In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 303, no 1-2, p. 30-39Article in journal (Refereed)
    Abstract [en]

    Transfer of work material to the tool surface is a common problem in many metal forming and metal working operations, especially in the case of work materials with a high adhesion tendency e.g. stainless steel, aluminum and titanium. In many operations, material transfer occurs already during the initial contact and with time it may result in degradation and roughening of the tool surface which will affect the surface quality of the formed or machined work material surface, e.g. problems related to galling in sheet metal forming. In the present study, the mechanisms behind the initial stages of material transfer between stainless steel and tool steel have been investigated under well controlled laboratory conditions and analyzed using optical surface profilometry and scanning electron microscopy.The results show that, independent of tool surface topography, transfer of stainless steel occurs already after a very short sliding distance. Depending on the tool steel surface topography, initial transfer occurs on two different scales. For a fine polished tool steel surface, fine scale transfer occurs in connection to protruding hard phase particles (carbides and carbonitrides) while for a ground rough surface large scale transfer occurs in connection to grinding scratches, where these act to mechanically scrape off material resulting in lumps off stainless steel on the tool steel surface. Also, sliding perpendicular to the grinding scratches results in more severe material transfer as compared with sliding parallel to the grinding scratches. Finally, the present paper illuminates the usefulness of combining optical surface profilometry and scanning electron microscopy as a powerful analytical tool when it comes to understanding the mechanisms controlling material transfer in a sliding contact on a Όm-scale level. © 2013 Elsevier B.V.

  • 127.
    Saketi, Sara
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. Uppsala University.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology. Uppsala University.
    Wear mechanism of cemented carbide cutting tool in the turning of 316L stainless steel2018Conference paper (Refereed)
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  • 128.
    Saketi, Sara
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Östby, Jonas
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    On the diffusion wear of cemented carbide in the turning of 316L austenitic stainless steel2019In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 430-431, p. 202-213Article in journal (Refereed)
    Abstract [en]

    The present study focuses on the wear and wear mechanisms of three different cemented carbide grades during orthogonal turning of 316L austenitic stainless steel at different cutting speeds. The influence of WC grain size and cutting speed on the resulting crater and flank wear was evaluated by optical surface profilometry and scanning electron microscopy (SEM). The mechanisms behind the crater and flank wear were characterized on the sub-micrometer scale using high resolution SEM, energy dispersive X-ray spectroscopy (EDS), Auger electron spectroscopy (AES) and time of flight secondary ion mass spectrometry (ToF-SIMS) of the worn cutting inserts and the produced chips.

    The results show that the wear rate of cemented carbide drastically increases with increasing cutting speed and that the wear is dependent on the WC grain size; i.e. the crater wear decreases with increasing WC grain size while the flank wear increases with increasing WC grain size. High resolution SEM, AES and ToF-SIMS analysis of the worn cemented carbide within the crater and flank wear regions reveal that the degradation of cemented carbide at higher cutting speeds is mainly controlled by diffusion wear of the WC-phase. This is confirmed by ToF-SIMS analysis of the back-side of stainless steel chips which reveals the presence of a 10 nm thin W-containing oxide film. The results are discussed and interpreted in the light of the conditions prevailing at the tool-chip interface.

  • 129.
    Saketi, Sara
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. Ångström Tribomaterials Group, Uppsala University.
    Odelros, S.
    Östby, J.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology. Ångström Tribomaterials Group, Uppsala University.
    Experimental study of wear mechanisms of cemented carbide in the turning of Ti6Al4V2019In: Materials, E-ISSN 1996-1944, Vol. 12, no 7, article id 2822Article in journal (Refereed)
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  • 130.
    Saketi, Sara
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Odelros, Stina
    Östby, Jonas
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Wear and wear mechanisms of cemented carbide in the turning of Ti6Al4V2019In: Materials, ISSN 1996-1944, E-ISSN 1996-1944Article in journal (Refereed)
    Abstract [en]

    Titanium and titanium alloys such as Ti-6Al-4V are generally considered as difficult-to-machine materials. This is mainly due to their high chemical reactivity, poor thermal conductivity and high strength, which is maintained at elevated temperatures. As a result, the cutting tool is exposed to rather extreme contact conditions resulting in plastic deformation and wear. In the present work, the mechanisms behind the crater and flank wear of uncoated cemented carbide inserts in the turning of Ti6Al4V are characterized using high resolution scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and high resolution Auger electron spectroscopy (AES).

    The results show that for combinations of low cutting speeds and feeds crater and flank wear were found to be controlled by an attrition wear mechanism while for combinations of medium to high cutting speeds and feeds a diffusion wear mechanism was found to control the wear. For the latter combinations, high resolution SEM and AES analysis reveal the formation of an approximately 100 nm thick carbon depleted WC-layer at the cemented carbide/Ti6Al4V interface due to the diffusion of carbon into the adhered build-up layers of work material on the rake and flank surfaces.

  • 131.
    Saketi, Sara
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. Ångström Tribomaterials group, Uppsala University.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology. Ångström Tribomaterials group, Uppsala University.
    Influence of CVD and PVD coating micro topography on the initial material transfer of 316L stainless steel in sliding contacts: A laboratory study2017In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 388-389, p. 29-38Article in journal (Refereed)
    Abstract [en]

    Austenitic stainless steels generally display poor tribological properties in sliding contacts partly due to their strong adhesion and transfer tendency to the counter surface. As a result machining of austenitic stainless steels is frequently associated with significant problems such as high stresses and high temperatures resulting in rapid tool wear. In the present study, the influence of coating micro topography on the initial material transfer of 316L stainless steel in sliding contacts has been evaluated using a scratch testing equipment. Coating materials include modern CVD Ti(C,N)-Al2O3-TiN and PVD (Ti,Al)N-(Al,Cr2)O3 coatings deposited on cemented carbide and pre- and post-coating grinding and polishing treatments were used to obtain different micro topographies of the coating surface. Pre- and post-test characterization of the surfaces was performed using high resolution scanning electron microscopy, energy dispersive X-ray spectroscopy and optical surface profilometry.

    The results show that the intrinsic topography of the as-deposited CVD and PVD coatings promotes material transfer. For the as-deposited CVD coating the nanoscale topography of the crystals controls the transfer while for the PVD coating the µm-scale droplets and craters control the transfer. Post-polishing of the coating, especially in combination with pre-polishing of the substrate, significantly improves the tribological performance of the surface reducing the friction coefficient and the material transfer tendency. However, the presence of µm sized droplets and craters in the PVD coating limit the possibility to obtain a smooth post-polished surface and its resistance to material pick-up. In contrast, post-polishing of the CVD coating does not suffer from intrinsic coating defects which results in low friction and a very high resistance to material pick-up.

  • 132.
    Saketi, Sara
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. Uppsala Universitet.
    Sveen, Susanne
    Dalarna University, School of Technology and Business Studies, Materials Technology. Linköpings Universitet.
    Gunnarsson, S
    Uddeholm Tooling.
    M’Sauobi, R
    Seco Tools.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Wear of a high cBN content PCBN cutting tool during hard milling of powder metallurgy cold work tool steels2015In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 332, p. 752-761Article in journal (Other academic)
    Abstract [en]

    The wear characteristics of a high cBN content PCBN cutting tool during hard milling of two different hardened cold work tool steels have been evaluated. Post-cutting examination of the worn cutting inserts was performed using high resolution field emission gun scanning electron microscopy, energy dispersive X-ray spectroscopy, Auger electron spectroscopy and optical surface profilometry. Also, the machined work material surfaces and collected chips were characterized in order to evaluate the prevailing wear mechanisms. The results show that both flank and crater wear are controlled by continuous wear due to tribochemical reactions, adhesive wear and mild abrasive wear. Besides, the cutting inserts show a tendency to micro-chipping along the cutting edge especially at higher cutting speed. The latter mechanism was also found to be dependent on type of work material. High lateral resolution Auger electron spectroscopy of the crater region shows that the worn surface is covered by a thin SixOy rich tribofilm with a thickness of 50-500 nm, the tribofilm being thicker on the binder phase regions. Also, the Co-rich regions of the binder phase seem to be more tribochemically affected by the prevailing contact conditions as compared with the W-rich regions of the binder phase and the cBN phase. 

  • 133.
    Saketi, Sara
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. Ångström Tribomaterials Group, Uppsala University.
    Östby, J.
    AB Sandvik Coromant, Sandviken.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology. Ångström Tribomaterials Group, Uppsala University.
    Influence of tool surface topography on the material transfer tendency and tool wear in the turning of 316L stainless steel2016In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 368–369, p. 239-252Article in journal (Refereed)
    Abstract [en]

    Abstract The influence of tool surface topography on the initiation and build-up of transfer layers in the orthogonal turning of 316L austenitic stainless steel have been studied under well controlled conditions. Tool materials include CVD Ti(C,N)-Al2O3-TiN and PVD (Ti, Al)N-(Al,Cr)2O3 coated cemented carbide inserts prepared using different grinding and polishing treatments. Post-test characterization of the inserts was performed using high resolution scanning electron microscopy and energy dispersive X-ray spectroscopy. The results show that the transfer tendency of work material is strongly affected by the surface topography of the rake face. For both types of inserts, the initial transfer and the build-up of transfer layers are localised to microscopic surface irregularities on the rake face. Consequently, an appropriate surface treatment of the cemented carbide substrate before coating deposition and the as-deposited CVD and PVD coating can be used in order to reduce the transfer tendency and the mechanical interaction between the mating surfaces. Also, an improved surface finish was found to reduce coating wear and consequently the crater wear rate of the inserts investigated. This can most likely be explained by the reduced tendency to discrete chipping of coating fragments in the contact zone and the formation of a thin transfer layer composed of Al, Si, Ca, O with beneficial friction properties which are promoted by a smooth coating surface.

  • 134.
    Saketi, Sara
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. Uppsala universitet.
    Östby, Jonas
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    A methodology to systematically investigate the diffusion degradation of cemented carbide during machining2019In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, no 14, article id 2271Article in journal (Refereed)
    Abstract [en]

    Using Ti6Al4V as a work material, a methodology to systematically investigate the diffusion degradation of cemented carbide during machining is proposed. The methodology includes surface characterization of as-tested worn inserts, wet etched worn inserts, metallographic cross-sectioned worn inserts as well as the back-side of the produced chips. Characterization techniques used include scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Auger electron spectroscopy (AES) and time of flight secondary ion mass spectroscopy (ToF-SIMS).

    The results show that the characterization of wet etched worn inserts give quick and useful information regarding the diffusion degradation of cemented carbide, in the present work the formation of a fine crystalline W layer (carbon depleted WC layer) at the tool / work material interface. The present study also illuminates the potential of AES analysis when it comes to analyzing the degradation of cemented carbide in contact with the work material during machining. The high surface sensitivity in combination with high lateral resolution makes it possible to analyze the worn cemented carbide surface on a sub-µm level. Especially AES sputter depth profiling, resulting in detailed information of variations in chemical composition across interfaces, is a powerful tool when it comes to understanding diffusion wear. Finally, the present work illustrates the importance of analyzing not only the worn tool but also the produced chips. An accurate characterization of the back-side of the chips will give important information regarding the wear mechanisms taking place at the tool rake face / chip interface. Surface analysis techniques such as AES and ToF-SIMS are well suited for this type of surface characterization.

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  • 135.
    Saketi, Sara
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. Uppsala universitet.
    Östby, Jonas
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology. Uppsala universitet.
    Wear behaviour of two different cemented carbide grades in turning 316 L stainless steel2018In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 941, p. 2367-2372Article in journal (Refereed)
    Abstract [en]

    Cemented carbides are the most common cutting tools for machining various grades of steels. In this study, wear behavior of two different cemented carbide grades with roughly the same fraction of binder phase and carbide phase but different grain size, in turning austenitic stainless steel is investigated. Wear tests were carried out against 316L stainless steel at 180 and 250 m/mincutting speeds. The worn surface of cutting tool is characterized using high resolution scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Auger electron spectroscopy (AES) and 3D optical profiler.The wear of cemented carbide in turning stainless steel is controlled by both chemical and mechanical wear. Plastic deformation, grain fracture and chemical wear is observed on flank and rake face of the cutting insert. In the case of fine-grained, the WC grains has higher surface contact with the adhered material which promotes higher chemical reaction and degradation of WC grains, so chemical wear resistance of the composites is larger when WC grains are larger. The hardness of cemented carbide increase linearly by decreasing grain size, therefore mechanical wear resistance of the composites is larger when WC grains are smaller.

  • 136.
    Schultheiss, F
    et al.
    Lunds Universitet.
    Fallqvist, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    M’Sauobi, R
    Seco Tools.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Ståhl, J E
    Lunds Universitet.
    Influence of CVD Al2O3 coated tool surface micro topography on the tribological characteristics in metal cutting: part II2013In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 298, p. 23-31Article in journal (Refereed)
    Abstract [en]

    The tribological conditions at the contact between the cutting tool and the chip are of great importance when analyzing the machining process. By knowing the contact conditions on the rake face of the cutting tool the wear on the clearance and rake face may be predicted in terms of size and type of wear. A certain value of the surface stresses is often thought of as leading to a higher wear rate of the cutting tool and thus a shorter tool life. In this article two different methods for experimentally measuring the contact condition on the clearance and rake face of the cutting tool are presented and illustrated with results obtained while turning AISI 4140. Results are also obtained in terms of how the surface roughness value of the cutting tool influences the contact condition. It was found that the tool surface topography may have a significant impact on the tribological performance during machining.

  • 137.
    Surreddi, Kumar Babu
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Oikonomou, C.
    Uddeholms AB, SE-68385 Hagfors, Sweden..
    Karlsson, P.
    Orebro Univ, Dept Mech Engn, SE-70182 Orebro, Sweden..
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Pejryd, L.
    Orebro Univ, Dept Mech Engn, SE-70182 Orebro, Sweden..
    In-situ micro-tensile testing of additive manufactured maraging steels in the SEM: Influence of build orientation, thickness and roughness on the resulting mechanical properties2018In: La Metallurgia Italiana, ISSN 0026-0843, no 3, p. 27-33Article in journal (Refereed)
    Abstract [en]

    Selective laser melting (SLM) is frequently used additive manufacturing technique capable of producing various complex parts including thin-wall sections. However the surface roughness is a limiting factor in thin sections produced by SLM process when strength is the main criterion. In this study, the influence of build orientation, thickness and roughness on the resulting mechanical properties of as-built test samples was investigated. Various thin sheets of EN 1.2709 maraging steel built in horizontal and vertical orientations produced by SLM were investigated using in-situ micro-tensile testing in a scanning electron microscope. The mechanical strength and deformation mechanisms were analyzed and explained based on thickness and build orientation. Increased ductility was observed in thicker samples as well as in the horizontal build samples. The results illustrate the potential of the in-situ test technique and aspects important to consider in design guidelines for thin AM structures.

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  • 138.
    Surreddi, Kumar Babu
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Oikonomou, Christos
    Karlsson, Patrik
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Pejryd, Lars
    In-situ Micro-tensile Testing of Additive Manufactured Maraging Steels in the SEM: Influence of Build Orientation, Thickness and Roughness on the Resulting Mechanical Properties2017In: Proceedings Euro PM 2017: International Powder Metallurgy Congress and Exhibition2017: Session 30: Mechanical Behaviour of AM Materials, 2017, article id Session 30Conference paper (Refereed)
    Abstract [en]

    Selective laser melting (SLM) is frequently used additive manufacturing technique capable of producing various complex parts including thin-wall sections. However the surface roughness is a limiting factor in thin sections produced by SLM process when strength is the main criterion. In this study, the influence of build orientation, thickness and roughness on the resulting mechanical properties of as-built test samples was investigated. Various thin sheets of EN 1.2709 maraging steel built in horizontal and vertical orientations produced by SLM were investigated using in-situ micro-tensile testing in a scanning electron microscope. The mechanical strength and deformation mechanisms were analyzed and explained based on thickness and build orientation. Increased ductility was observed in thicker samples as well as in the horizontal build samples. The results illustrate the potential of the in-situ test technique and aspects important to consider in design guidelines for thin AM structures.

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    fulltext
  • 139.
    Surreddi, Kumar Babu
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Wear of cemented carbide nibs in steel wire drawing2018In: The 18th Nordic Symposium on Tribology – NORDTRIB 2018 / [ed] Prof. Staffan Jacobson, 2018Conference paper (Other academic)
    Abstract [en]

    The tribological interaction between a cemented carbide drawing die and a steel wire under lubricated wire drawing conditions has been characterized using 3D optical surface profilometry, scanning electron microscopy and energy dispersive X-ray spectroscopy. The results show that wear of the cemented carbides mainly is located to three different wear zones, i) at the entrance of the reduction zone, ii) at the exit of the reduction zone/ entrance of the bearing zone and iii) at the exit of the bearing zone. In the first wear zone, wear of the cemented carbide occurs on a WC grain size level and is controlled by plastic deformation, cracking and fragmentation of individual WC grains. In the second wear zone, wear of the cemented carbide is controlled by chipping of small WC/Co composite fragments resulting in craters, ~ 10μm in diameter.

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  • 140.
    Surreddi, Kumar Babu
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Yvell, Karin
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Norgren, Susanne
    Sandvik Mining and Rock Technology, Rock Tools division, Sweden; Department of Engineering Sciences, Uppsala University, Sweden.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Characterization of surface degradation and wear damage Of cemented carbide in rock drilling2018In: The 18th Nordic Symposium on Tribology – NORDTRIB 2018 / [ed] Prof. Staffan Jacobson, 2018Conference paper (Other academic)
    Abstract [en]

    In this work, worn top hammer drill bit buttons after underground drifting in Granodiorite are analysed using scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and electron backscatter diffraction (EBSD) to understand the dominant surface failure and wear mechanisms on the flank wear land region, i.e. the outer side of the gauge row cemented carbide buttons. SEM shows that the worn surface of the flank wear land is partly covered with islands of a thin rock material transfer layer and that the exposed cemented carbide show deformed, cracked and fragmented WC grains. AES gives that the transferred rock material is mainly located on the surface but may penetrate into cemented carbide microstructure to a depth of 1-2 WC grain diameters. Finally, EBSD reveals that the deformation of the cemented carbide in the flank wear land region is located to a thin zone, about ~10 μm in depth.

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  • 141.
    Sveen, Susanne
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. Linköping University, SE-581 83 Linköping, Sweden.
    Andersson, J
    Seco Tools.
    M’Sauobi, R
    Seco Tools.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Scratch adhesion characteristics of PVD TiAlN deposited on high speed steel, cemented carbide and PCBN substrates2013In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 308, no 1-2, p. 133-141Article in journal (Refereed)
    Abstract [en]

    Modern tool materials, ranging from powder metallurgical high speed steel to super hard materials such as polycrystalline cubic boron nitride and diamond, are used as cutting tools in the metal cutting industry. In order to further improve the cutting performance, these tools are frequently coated by thin, hard PVD coatings such as TiN, TiAlN, AlCrO3, etc. In order to develop and design new PVD coatings it is important to characterize the mechanical properties of the coatings and understand the coating/substrate deformation mechanisms in a tribological contact, e.g. metal cutting. For example, it is important to be aware that the mechanical properties of the substrate (tool material) have a significant impact on the practical coating adhesion and the coating failure mechanisms.

    In the present study scratch testing has been used in order to evaluate to increase the understanding of the mechanical response and potential coating failure modes of cathodic arc evaporated TiAlN deposited on high speed steel, cemented carbide and polycrystalline cubic boron nitride. Post-test characterization of the scratched samples using optical profilometry, scanning electron microscopy and energy dispersive X-ray spectroscopy were performed and the cohesive and adhesive surface failure mechanisms are described and related to the substrate material properties. The results clearly show that, although all substrate materials can be regarded as hard, they result in completely different coating failure mechanisms at the normal load corresponding to substrate exposure. Also, coating failure resulting in substrate exposure does not necessarily correspond to interfacial cracking resulting in adhesive fracture along the coating-substrate interface.

  • 142.
    Sveen, Susanne
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology. Linköpings Universitet.
    M’Sauobi, R
    Seco Tools.
    Bexell, Ulf
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    PCBN hard turning of ball bearing steel: Influence of PVD coating deposition on tool wear and surface finish/surface integrity of machined surfaceManuscript (preprint) (Other academic)
  • 143. Wadman, Boel
    et al.
    Eriksson, Jenny
    Dalarna University, School of Technology and Business Studies, Material Science.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Schedin, Erik
    Madsen, Erik
    Bay, Niels
    Influence of surface texture on the galling characteristics of lean duplex and austenitic stainless steels2010In: Duplex World 2010 Conference & Exhibition, Beaune, France, 2010Conference paper (Other academic)
    Abstract [en]

    Two simulative test methods were used to study galling in sheet forming of two types of stainless steel sheet: austenitic (EN 1.4301) and lean duplex LDX 2101 (EN 1.4162) in different surface conditions. The pin-on-disc test was used to analyse the galling resistance of different combinations of sheet materials and lubricants. The strip reduction test, a severe sheet forming tribology test was used to simulate the conditions during ironing. This investigation shows that the risk of galling is highly dependent on the surface texture of the duplex steel. Trials were also performed in an industrial tool used for high volume production of pump components, to compare forming of LDX 2101 and austenitic stainless steel with equal thickness. The forming forces, the geometry and the strains in the sheet material were compared for the same component. It was found that LDX steels can be formed to high strain levels in tools normally applied for forming of austenitic steels, but tool adaptations are needed to comply with the higher strength and springback of the material.

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  • 144.
    Westlund, V.
    et al.
    Uppsala Univ, Angstrom Tribomat Grp, Box 534, S-75121 Uppsala, Sweden..
    Heinrichs, J.
    Uppsala Univ, Angstrom Tribomat Grp, Box 534, S-75121 Uppsala, Sweden..
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology. Uppsala Univ, Angstrom Tribomat Grp, Box 534, S-75121 Uppsala, Sweden.
    Jacobson, S.
    Uppsala Univ, Angstrom Tribomat Grp, Box 534, S-75121 Uppsala, Sweden..
    Investigation of material transfer in sliding friction-topography or surface chemistry?2016In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 100, p. 213-223Article in journal (Refereed)
    Abstract [en]

    To differentiate between the roles of surface topography and chemical composition on influencing friction and transfer in sliding contact, a series of tests were performed in situ in an SEM. The initial sliding during metal forming was investigated, using an aluminum tip representing the work material, put into sliding contact with a polished flat tool material. Both DLC-coated and uncoated tool steel was used. By varying the final polishing step of the tool material, different surface topographies were obtained. The study demonstrates the strong influence from nano topography of an unpolished DLC coated surface on both coefficient of friction and material transfer. The influence of tool surface chemistry is also discussed.

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  • 145.
    Wiklund, Urban
    et al.
    Uppsala University.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Jacobson, Staffan
    Uppsala University.
    Degradation mechanisms of matrix steel in rock drill bits2016In: Proceedings of the 17th Nordic Symposium on Tribology - Nordtrib 2016, 2016Conference paper (Refereed)
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