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Brodin, Håkan
Publications (10 of 46) Show all publications
Eriksson, R., Brodin, H., Johansson, S., Östergren, L. & Li, X.-H. (2014). Fractographic and microstructural study of isothermally and cyclically heat treated thermal barrier coatings. Surface & Coatings Technology, 243, 82-90.
Open this publication in new window or tab >>Fractographic and microstructural study of isothermally and cyclically heat treated thermal barrier coatings
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2014 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 243, 82-90 p.Article in journal (Refereed) Published
Abstract [en]

The fracture surfaces from adhesion tested thermal barrier coatings (TBC) have been studied by scanning electron microscopy. The adhesion test have been made using the standard method described in ASTM 633, which makes use of a tensile test machine to measure the adhesion. The studied specimens consist of air plasma sprayed (APS) TBC deposited on disc-shaped substrates of Hastelloy X. The bond coat (BC) is of NiCoCrAlY type and the top coat (TC) consists of yttria–stabilised–zirconia. Before the adhesion test, the specimens were subjected to three different heat treatments: 1) isothermal oxidation 2) thermal cycling fatigue (TCF) and 3) burner rig test (BRT). The fracture surfaces of the adhesion tested specimens where characterised. A difference in fracture mechanism were found for the different heat treatments. Isothermal oxidation gave fracture mainly in the top coat while the two cyclic heat treatments gave increasing amount of BC/TC interface fracture with number of cycles. Some differences could also be seen between the specimens subjected to burner rig test and furnace cycling.

Keyword
Thermal barrier coating, TBC, fractography, adhesion, thermal cycling, burner rig
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-67883 (URN)10.1016/j.surfcoat.2012.02.040 (DOI)000335542100014 ()
Note

On the day of the defence date of the Thesis the status of this article was Manuscript.

Available from: 2011-05-02 Created: 2011-05-02 Last updated: 2017-12-11Bibliographically approved
Eriksson, R., Brodin, H., Johansson, S., Östergren, L. & Li, X.-H. (2014). Thermal Cycling Fatigue of Thermal Barrier Coatings- Rig and Experiment Design. In: : . Paper presented at Fatigue 2014 11th International Fatigue Congress, Melbourne, Australia, 2-7 March, 2014. (pp. 641-646). Trans Tech Publications Inc., 891-892.
Open this publication in new window or tab >>Thermal Cycling Fatigue of Thermal Barrier Coatings- Rig and Experiment Design
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2014 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Ceramic thermal barrier coatings are used for thermal insulation in gas turbines to protect metallic components from high-temperature degradation. The ceramic coating may, due to its different coefficient of thermal expansion, crack and spall off the metallic component, thus rendering the component unprotected against high-temperature. Thermal cycling rigs of various designs are used to evaluate the durability of thermal barrier coatings. The present paper reports the result from a round robin test including three thermal cycling rigs at different locations. To better understand the influence of rig design on the thermal cyclic lives of thermal barrier coatings, some test parameters, such as the material of the specimen table and the cooling rate, were varied in one of the rigs. Furthermore, two different specimen geometries, rectangular and disc-shaped, were tested. The specimen table material was found to greatly influence the cooling rate of the specimens, more so than variations in the cooling airflow. The rectangular specimens were found to be more sensitive to test setup than the disc-shaped specimens; under certain conditions, the rectangular specimens could be made to fracture from the long side, rather than the short side of the specimen edge, which shortened the thermal cyclic life of the coatings.

Place, publisher, year, edition, pages
Trans Tech Publications Inc., 2014
Keyword
thermal barrier coating, TBC, thermal cycling, rig, test parameters, round robin
National Category
Engineering and Technology Materials Engineering
Identifiers
urn:nbn:se:liu:diva-104662 (URN)10.4028/www.scientific.net/AMR.891-892.641 (DOI)000337767700100 ()
Conference
Fatigue 2014 11th International Fatigue Congress, Melbourne, Australia, 2-7 March, 2014.
Available from: 2014-02-20 Created: 2014-02-20 Last updated: 2014-12-10
Eriksson, R., Brodin, H., Johansson, S., Östergren, L. & Li, X.-H. (2013). Cyclic Hot Corrosion of Thermal Barrier Coatings and Overlay Coatings. In: Proceedings of ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT2013: . Paper presented at ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT2013, San Antonio, Texas, USA, June 3-7, 2013 (pp. 1-8). The American Society of Mechanical Engineers (ASME), 4.
Open this publication in new window or tab >>Cyclic Hot Corrosion of Thermal Barrier Coatings and Overlay Coatings
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2013 (English)In: Proceedings of ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT2013, The American Society of Mechanical Engineers (ASME) , 2013, Vol. 4, 1-8 p.Conference paper, Published paper (Refereed)
Abstract [en]

The influence, and interdependence, of water vapor and Na2SO4–50 mol% NaCl on the oxidation of a NiCoCrAlY coating and a thermal barrier coating (TBC) were studied at 750 °C. Water vapor was found to have a negligible effect on oxide composition, but influenced the oxide morphology on the NiCoCrAlY coating. Na2SO4–50 mol% NaCl deposits on the coatings influencedoxide composition, most notably by the promotion of a Y rich phase. The effect of Na2SO4–50 mol% NaCl deposits was also evident for the TBC coated specimen, where the formed metal/ceramic interface oxide was affected by salt reaching the interface by penetration of the zirconia TBC.

Place, publisher, year, edition, pages
The American Society of Mechanical Engineers (ASME), 2013
National Category
Materials Engineering
Identifiers
urn:nbn:se:liu:diva-95556 (URN)10.1115/GT2013-95526 (DOI)000361499900009 ()978-0-7918-5518-8 (ISBN)
Conference
ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT2013, San Antonio, Texas, USA, June 3-7, 2013
Note

Paper No. GT2013-95526

Available from: 2013-07-08 Created: 2013-07-08 Last updated: 2016-05-13Bibliographically approved
Moverare, J., Leijon, G., Brodin, H. & Palmert, F. (2013). Effect of SO2 and water vapour on the low-cycle fatigue properties of nickel-base superalloys at elevated temperature. Materials Science & Engineering: A, 564, 107-115.
Open this publication in new window or tab >>Effect of SO2 and water vapour on the low-cycle fatigue properties of nickel-base superalloys at elevated temperature
2013 (English)In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 564, 107-115 p.Article in journal (Refereed) Published
Abstract [en]

In this study the effect of SO2+water vapour on strain controlled low cycle fatigue resistance of three different nickel based superalloys has been studied at 450 °C and 550 °C. A negative effect was found on both the crack initiation and crack propagation process. The effect increases with increasing temperature and is likely to be influenced by both the chemical composition and the grain size of the material. In general the negative effect decreases with decreasing strain range even if this means that the total exposure time increases. This is explained by the importance of the protective oxide scale on the specimen surface, which is more likely to crack when the strain range increases. When the oxide scale cracks, preferably at the grain boundaries, oxidation can proceed into the material, causing preferable crack initiation sites and reduced fatigue resistance.

Place, publisher, year, edition, pages
Elsevier, 2013
Keyword
Nickel based superalloys, Low cycle fatigue, Environmental effect, Sulphur, Water vapour
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:liu:diva-86862 (URN)10.1016/j.msea.2012.11.079 (DOI)000315748100016 ()
Available from: 2013-01-07 Created: 2013-01-07 Last updated: 2017-12-06Bibliographically approved
Eriksson, R., Sjöström, S., Brodin, H., Johansson, S., Östergren, L. & Li, X.-H. (2013). Influence of Interface Roughness on the Fatigue Life of Thermal Barrier Coatings. In: : . Paper presented at 13th International Conference on Fracture, June 16-21, 2013, Beijing, China (pp. 1-10). .
Open this publication in new window or tab >>Influence of Interface Roughness on the Fatigue Life of Thermal Barrier Coatings
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2013 (English)Conference paper, Published paper (Refereed)
Keyword
thermal barrier coating, interface, roughness, fatigue
National Category
Engineering and Technology Materials Engineering
Identifiers
urn:nbn:se:liu:diva-95555 (URN)
Conference
13th International Conference on Fracture, June 16-21, 2013, Beijing, China
Available from: 2013-07-08 Created: 2013-07-08 Last updated: 2013-07-08
Eriksson, R., Johansson, S., Brodin, H., Broitman, E., Östergren, L. & Li, X.-H. (2013). Influence of substrate material on the life of atmospheric plasmas prayed thermal barrier coatings. Surface & Coatings Technology, 232(15), 795-803.
Open this publication in new window or tab >>Influence of substrate material on the life of atmospheric plasmas prayed thermal barrier coatings
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2013 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 232, no 15, 795-803 p.Article in journal (Refereed) Published
Abstract [en]

Thermal barrier coatings (TBCs) are used in gas turbines to prolong the life of the underlying substrates and to increase the efficiency of the turbines by enabling higher combustion temperatures. TBCs may fail during service due to thermal fatigue or through the formation of non-protective thermally grown oxides (TGOs). This study compares two atmospheric plasma sprayed (APS) TBC systems comprising of two identical TBCs deposited on two different substrates (Haynes 230 and Hastelloy X). The thermal fatigue life was found to differ between the two TBC systems. The interdiffusion of substrate elements into the coating was more pronounced in the TBC system with shorter life, however, very few of the substrate elements (only Mn and to some extent Fe) formed oxides in the bond coat/top coat interface. Fractography revealed no differences in the fracture behaviour of the TBCs; the fracture occurred, in both cases, to about 60% in the top coat close to the interface and the remainder in the interface. Nanoindentation revealed only small differences in mechanical properties between the TBC systems and a finite element crack growth analysis showed that such small differences did not cause any significant change in the crack driving force. The oxidation kinetics was found to be similar for both TBC systems for the formation of Al2O3 but differed for the kinetics of non-Al2O3 TGOs where the TBC system with shortest life had a faster formation of non-Al2O3 TGOs caused by a faster Al depletion. The difference in non-Al2O3 TGO growth kinetics was considered to be the main reason for the difference in life.

Place, publisher, year, edition, pages
Elsevier, 2013
Keyword
Thermal barrier coating; TBC; Substrate influence; Interdiffusion; Fatigue life; Oxidation kinetics
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-96810 (URN)10.1016/j.surfcoat.2013.06.101 (DOI)000327691300103 ()
Available from: 2013-08-27 Created: 2013-08-27 Last updated: 2017-12-06Bibliographically approved
Brodin, H., Andersson, O. & Johansson, S. (2013). Mechanical Behaviour and Microstructure Correlation in a Selective Laser Melted Superalloy. In: ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. Paper presented at ASME Turbo Expo 2013: Turbine Technical Conference and Exposition,GT2013, San Antonio, Texas, USA, June 2-7 2013 (pp. 1-7). American Society of Mechanical Engineers (ASME), 5A.
Open this publication in new window or tab >>Mechanical Behaviour and Microstructure Correlation in a Selective Laser Melted Superalloy
2013 (English)In: ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, American Society of Mechanical Engineers (ASME) , 2013, Vol. 5A, 1-7 p.Conference paper, Published paper (Refereed)
Abstract [en]

Selective laser melting (SLM), or, as the industry standard denotes the process, laser sintering, is an additive manufacturing process where metal powder is melted by a laser source layer-wise, forming a solid, dense metallic component. With the SLM process, near net shape components can be manufactured directly from a CAD model. The model is sliced into thin (max 100μm thick) layers. Powder is spread onto a metallic build platform and the powder is fused by a laser as dictated by the CAD model. The laser energy is intense enough to permit full melting (welding) of the particles to form solid metal. The process is repeated layer by layer until the part is complete.

A number of materials are available, including steel, aluminium, titanium and, in recent time, also superalloys. The material investigated in the current project is an alloy in agreement with the composition of Haynes International Hastelloy X, a solution strengthened superalloy typically used in large welded components exposed to high temperatures in oxidizing as well as reducing environments.

Microstructurally, the material is different from both a hot-rolled, as well as a cast material due to the manufacturing process. Since the SLM process involves laser melting of powder particles in the size range of <50μm, the structure resembles of a weld structure, however on a smaller scale. Due to the layer-by-layer build strategy, the material will exhibit anisotropy. Different heat treatment approaches can be adopted in order to homogenize the material and to minimize the effect of anisotropy. A stress relieve heat treatment was adopted and compared to the findings of the as manufactured SLM material.

The current project focuses on evaluating mechanical properties for a material manufactured by the SLM process and comparing to data for established manufacturing processes. For evaluation of the mechanical properties, low cycle fatigue testing and tensile testing has been performed. The microstructure and material deformation / cracking are evaluated by light optical microscopy and SEM, where electron backscatter diffraction is used. Due to the weld-like structure, the material will be transversely isotropic in the as-manufactured condition with one symmetry plane perpendicular to the build direction. Any direction perpendicular to the build direction tends to give increased strength compared to a direction parallel to the build direction if monotonic data are concerned. If fatigue properties are concerned, the anisotropy is also obvious. It is shown that the differences in behaviour can be coupled to microstructure.

Place, publisher, year, edition, pages
American Society of Mechanical Engineers (ASME), 2013
National Category
Materials Engineering
Identifiers
urn:nbn:se:liu:diva-97014 (URN)10.1115/GT2013-95878 (DOI)000361500100019 ()978-0-7918-5519-5 (ISBN)
Conference
ASME Turbo Expo 2013: Turbine Technical Conference and Exposition,GT2013, San Antonio, Texas, USA, June 2-7 2013
Available from: 2013-09-03 Created: 2013-09-03 Last updated: 2016-05-13Bibliographically approved
Brodin, H. & Saarimäki, J. (2013). Mechanical Properties of Lattice Truss Structures Made of a Selective Laser Melted Superalloy. In: : . Paper presented at 13th International Conference on Fracture ICF13, June 16-21, Beijing, China. (pp. 1-10). .
Open this publication in new window or tab >>Mechanical Properties of Lattice Truss Structures Made of a Selective Laser Melted Superalloy
2013 (English)Conference paper, Published paper (Refereed)
Keyword
free form fabrication, selective laser melting, superalloys, tensile testing, lattice
National Category
Engineering and Technology Materials Engineering
Identifiers
urn:nbn:se:liu:diva-95433 (URN)
Conference
13th International Conference on Fracture ICF13, June 16-21, Beijing, China.
Available from: 2013-07-03 Created: 2013-07-03 Last updated: 2013-07-03
Eriksson, R., Sjöström, S., Brodin, H., Johansson, S., Östergren, L. & Li, X.-H. (2013). TBC bond coat-top coat interface roughness: influence on fatigue life and modelling aspects. Surface & Coatings Technology, 236, 230-238.
Open this publication in new window or tab >>TBC bond coat-top coat interface roughness: influence on fatigue life and modelling aspects
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2013 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 236, 230-238 p.Article in journal (Refereed) Published
Abstract [en]

Thermal barrier coatings (TBCs), when used in gas turbines, may fail through thermal fatigue, causing the ceramic top coat to spall off the metallic bond coat. The life prediction of TBCs often involves finite element modelling of the stress field close to the bond coat/top coat interface and thus relies on accurate modelling of the interface. The present research studies the influence of bond coat/top coat interface roughness on the thermal fatigue life of plasma sprayed TBCs. By using different spraying parameters, specimens with varying interface roughness were obtained. During thermal cycling it was found that higher interface roughness promoted longer thermal fatigue life. The interfaces were characterised by roughness parameters, such as Ra, Rq and Rq, as well as by autocorrelation, material ratio curves, probability plots and slope distribution. The variation of spray parameters was found to affect amplitude parameters, such as Ra, but not spacing parameters, such as RSm. Three different interface geometries were tried for finite element crack growth simulation: cosine, ellipse and triangular shape. The cosine model was found to be an appropriate interface model and a procedure for obtaining the necessary parameters, amplitude and wavelength, was suggested. The positive effect of high roughness on life was suggested to be due to a shift from predominantly interface failure, for low roughness, to predominantly top coat failure, for high roughness.

Keyword
thermal barrier coating, TBC, thermal cycling fatigue, interface, roughness, Ra
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-96811 (URN)10.1016/j.surfcoat.2013.09.051 (DOI)000329884300032 ()
Available from: 2013-08-27 Created: 2013-08-27 Last updated: 2017-12-06Bibliographically approved
Sjöström, S., Brodin, H. & Jinnestrand, M. (2013). Thermomechaical Fatigue Life of a TBC - Comparison of Computed and Measured Behaviour of Delamination Cracks. In: : . Paper presented at 13th International Conference on Fracture, June 16-21, 2013, Beijing, China (pp. 1-10). .
Open this publication in new window or tab >>Thermomechaical Fatigue Life of a TBC - Comparison of Computed and Measured Behaviour of Delamination Cracks
2013 (English)Conference paper, Published paper (Refereed)
Keyword
TBC, fracture-mechanical model, experimental, FEM, interface crack
National Category
Engineering and Technology Materials Engineering
Identifiers
urn:nbn:se:liu:diva-96381 (URN)
Conference
13th International Conference on Fracture, June 16-21, 2013, Beijing, China
Available from: 2013-08-16 Created: 2013-08-16 Last updated: 2013-08-16
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