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Zhu, B., Seifeddine, S., Jarfors, A. E. .., Leisner, P. & Zanella, C. (2019). A study of anodising behaviour of Al-Si components produced by rheocasting. Paper presented at 15th International conference on semi-solid processing of alloys and composites, October 22nd to 24th, 2018, Shenzhen, China. Solid State Phenomena, 285, 39-44
Open this publication in new window or tab >>A study of anodising behaviour of Al-Si components produced by rheocasting
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2019 (English)In: Solid State Phenomena, ISSN 1012-0394, E-ISSN 1662-9779, Vol. 285, p. 39-44Article in journal (Refereed) Published
Abstract [en]

This paper aims to investigate the anodising behaviour of Al-Si components produced by rheocasting, to understand the effect of the surface liquid segregation (SLS) on the anodising response. The material investigated was EN AC 42000 Al-alloy with an addition of 150 ppm Sr. The component was rheocast and conventionally liquid cast for benchmarking. The RheoMetalTM process was used to prepare slurry and subsequently cast using a vertical pressure die casting machine. Prior to anodising, mechanical grinding was used as pre-treatment method for selected samples as comparison with components in the as-cast state. Anodising was performed on the components using a constant controlled voltage at 25 V, in 1 M H2SO4, at room temperature. The duration of anodising was varied from 30 mins to 120 mins to examine the relationship between oxide layer thickness and the anodising time. The oxide layer was investigated and characterised. The results demonstrated that the presence of the SLS layer, which was enriched with alloying elements, had a significant influence on the anodising behaviour of the cast component. The oxide layer thickness of the components produced by rheocasting and fully liquid casting was measured and compared. The relations between the oxide layer thickness and anodising time, as well as the casting methods are presented and discussed in this paper.

Place, publisher, year, edition, pages
Trans Tech Publications, 2019
Keywords
Anodising, Oxide Layer, Rheocasting
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-42630 (URN)10.4028/www.scientific.net/SSP.285.39 (DOI)2-s2.0-85059944290 (Scopus ID)
Conference
15th International conference on semi-solid processing of alloys and composites, October 22nd to 24th, 2018, Shenzhen, China
Available from: 2019-01-14 Created: 2019-01-14 Last updated: 2019-05-09Bibliographically approved
Leisner, P. & Johansson, E. (2019). Aspects to be considered when making innovation out of promising research results in surface technology. Transactions of the Institute of Metal Finishing, 97(2), 67-72
Open this publication in new window or tab >>Aspects to be considered when making innovation out of promising research results in surface technology
2019 (English)In: Transactions of the Institute of Metal Finishing, ISSN 0020-2967, E-ISSN 1745-9192, Vol. 97, no 2, p. 67-72Article in journal (Refereed) Published
Abstract [en]

In the eyes of industrialists, scientists often exaggerate the economic potential of their findings. The industrialists know that developing a new technology to production is associated with uncertainty and risks. To elucidate the challenges faced by the surface treatment industry, this paper discusses aspects that should be considered when making innovation out of promising research results. The Technology Readiness Level (TRL) metric for assessing maturity of a technology is discussed and exemplified. Additional risks of fluid character such as legislation, price of raw material and customer expectations are also discussed. Even though, the subject is of general relevance, the present discussion refers to surface technology and examples are given from copper plating of printed circuit boards, and durable and cost-efficient coatings on electrical connectors. 

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Electric connectors, Printed circuit boards, Cost-efficient, Customer expectation, Economic potentials, Electrical connectors, Research results, Surface technology, Technology readiness levels, Uncertainty and risks, Surface treatment
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:hj:diva-43365 (URN)10.1080/00202967.2019.1561984 (DOI)000460164800005 ()2-s2.0-85062337067 (Scopus ID)
Available from: 2019-03-21 Created: 2019-03-21 Last updated: 2019-04-26Bibliographically approved
Leisner, P. & Nielsen, L. P. (2019). Offshoring and backshoring of surface finishing from the perspective of the Nordic countries. Transactions of the Institute of Metal Finishing, 97(2), 54-56
Open this publication in new window or tab >>Offshoring and backshoring of surface finishing from the perspective of the Nordic countries
2019 (English)In: Transactions of the Institute of Metal Finishing, ISSN 0020-2967, E-ISSN 1745-9192, Vol. 97, no 2, p. 54-56Article in journal (Refereed) Published
Abstract [en]

Backshoring of production to Western Europe has become an increasingly important trend after decades of offshoring. The subject is introduced by a general discussion followed by a specific analysis of the Nordic surface finishing industry. The main finding is that production quality is the main driver for backshoring of surface finishing. 

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
finishing, Market trends, Scandinavia, supplier, surface technology, Nordic countries, Production quality, Surface finishing, Surface finishing industry, Surface treatment
National Category
Production Engineering, Human Work Science and Ergonomics Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:hj:diva-43366 (URN)10.1080/00202967.2019.1571261 (DOI)000460164800002 ()2-s2.0-85062368213 (Scopus ID);JTHMaterialIS (Local ID);JTHMaterialIS (Archive number);JTHMaterialIS (OAI)
Available from: 2019-03-21 Created: 2019-03-21 Last updated: 2019-04-26Bibliographically approved
Leisner, P. & Zanella, C. (2018). Application of Assaf panel for evaluating throwing power of pulse reverse electroplating on complex geometries. Transactions of the Institute of Metal Finishing, 96(5), 258-264
Open this publication in new window or tab >>Application of Assaf panel for evaluating throwing power of pulse reverse electroplating on complex geometries
2018 (English)In: Transactions of the Institute of Metal Finishing, ISSN 0020-2967, E-ISSN 1745-9192, Vol. 96, no 5, p. 258-264Article in journal (Refereed) Published
Abstract [en]

The Assaf panel arrangement was used for evaluating pulse reverse plating processes and optimisation of the throwing power (TP) of complex three-dimensional (3D) geometries. Two different electroplating processes were investigated: an acid copper bath and a cyanide silver bath without additives. It has not been possible to establish a direct correlation factor for TP obtained with the Assaf panel and the 3D objects included in the trials. Nevertheless, the Assaf panel was found to be a useful tool for preliminary process parameter optimisation. The copper bath needs agitation to deposit coatings of good quality, whereas the silver bath obtains the best throwing power without agitation. The latter is probably due to inhibition by adsorbed cyanide.

Place, publisher, year, edition, pages
Taylor & Francis, 2018
Keywords
Throwing power; pulse reverse; silver; copper
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:hj:diva-41719 (URN)10.1080/00202967.2018.1507331 (DOI)000444095300006 ()2-s2.0-85053235016 (Scopus ID)PP JTH 2018 embargo 12 (Local ID)PP JTH 2018 embargo 12 (Archive number)PP JTH 2018 embargo 12 (OAI)
Available from: 2018-10-02 Created: 2018-10-02 Last updated: 2019-09-10Bibliographically approved
Ahmadkhaniha, D., Eriksson, F., Leisner, P. & Zanella, C. (2018). Effect of SiC particle size and heat-treatment on microhardness and corrosion resistance of NiP electrodeposited coatings. Journal of Alloys and Compounds, 769, 1080-1087
Open this publication in new window or tab >>Effect of SiC particle size and heat-treatment on microhardness and corrosion resistance of NiP electrodeposited coatings
2018 (English)In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 769, p. 1080-1087Article in journal (Refereed) Published
Abstract [en]

Electrodeposition of NiP composite coatings with nano and sub-micron sized SiC has been carried out to investigate the possibility of replacing hard chromium coatings. The composition and structure of the coatings were evaluated by energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analysis, respectively. Microhardness was measured by Vickers indentation and polarization measurements were carried out to study the corrosion behavior of the coatings. The results showed that submicron particles can be codeposited with a higher content as compared to nano sized ones. However, even if a smaller amount of the nano-sized SiC particles are incorporated in the coating, the contribution to an increasing microhardness was comparable with the submicron sized particles, which can be related to the higher density of codeposited particles. SiC particles did not change the anodic polarization behavior of NiP coatings in a 3.5% NaCl solution. Finally, the effect of heat-treatment on the coatings properties at 400 °C for 1 h was studied to investigate the contribution of particles and heat-treatment on hardness and corrosion properties. It was found that the heat-treatment doubled the microhardness and changed the anodic polarization behavior of the coatings from passive to active with respect to the as-plated conditions.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Electrodeposition, Heat-treatment, Microhardness, NiP, Polarization, SiC
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:hj:diva-41502 (URN)10.1016/j.jallcom.2018.08.013 (DOI)000449481200126 ()2-s2.0-85051683091 (Scopus ID)
Available from: 2018-09-19 Created: 2018-09-19 Last updated: 2019-04-26Bibliographically approved
Belov, I., Alavizadeh, Z., Lindgren, M., Ryden, J. & Leisner, P. (2018). Experimental and CFD evaluation of active anti-condensation methods for non-hermetic cabinets. In: 19th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE, 2018: . Paper presented at 19th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2018, 15 April 2018 through 18 April 2018 (pp. 1-6). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Experimental and CFD evaluation of active anti-condensation methods for non-hermetic cabinets
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2018 (English)In: 19th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE, 2018, Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 1-6Conference paper, Published paper (Refereed)
Abstract [en]

Experimental evaluation of several active anti-condensation methods for application in non-hermetic electronics enclosures was performed in harsh climatic conditions, including RH = 70% and T = 43 °C. The studied methods included blowing the air along the exposed surface, combination of blowing and air heating as well as local heating of the exposed surface in natural convection conditions. The purpose was to prevent/remove the dew on/from the exposed surface of a micro-condensation sensor. The difference between the methods was quantified in terms of time for dew removal. The power consumption aspects were discussed. A CFD based optimization methodology was developed to determine the heating profiles for the local anti-condensation PCB heater in a non-hermetic cabinet exposed to the quickly changing climatic conditions. The potential for 60% energy savings was revealed by simulation.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2018
Keywords
Heating systems, Surface treatment, Humidity, Plastics, Electron tubes, Temperature measurement, Bars
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-40927 (URN)10.1109/EuroSimE.2018.8369863 (DOI)2-s2.0-85048877385 (Scopus ID)9781538623596 (ISBN)
Conference
19th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2018, 15 April 2018 through 18 April 2018
Available from: 2018-07-03 Created: 2018-07-03 Last updated: 2018-09-19Bibliographically approved
Belov, V., Leisner, P., Mannikoff, A. & Belov, I. (2018). Mathematical Model of Multi-Phase Power Converter for Parallel Computation. International Journal of Emerging Electric Power Systems, 19(1), Article ID 20170114.
Open this publication in new window or tab >>Mathematical Model of Multi-Phase Power Converter for Parallel Computation
2018 (English)In: International Journal of Emerging Electric Power Systems, ISSN 2194-5756, E-ISSN 1553-779X, Vol. 19, no 1, article id 20170114Article in journal (Refereed) Published
Abstract [en]

A mathematical model of a multi-phase power conversion system composed of modified bridge-elements (B-system) capable for parallel computation has been developed. Experimental validation on the example of a power system including a synchronous generator and an AC-DC rectifier has been performed. A mathematical algorithm for B-system assembly and steps to obtain mathematical model of the B-system have been developed. Integration of mathematical models of conversion system into the complete model of a multi-phase power system has been explained and evaluation of computational efficiency of parallel computation techniques for the developed model of an AC-DC-AC converter has been performed. The presented modelling method can be employed in the design phase of smart grids, for power quality and conducted emission analysis. 

Place, publisher, year, edition, pages
Walter de Gruyter, 2018
Keywords
mathematical model, parallel computation, power converter, power quality, power system, rectifier, AC-AC power converters, Computational efficiency, Electric inverters, Electric power transmission networks, Mathematical models, Power converters, Quality control, Rectifying circuits, Smart power grids, AC-DC-AC converters, Conducted emissions, Experimental validations, Mathematical algorithms, Power conversion systems, Electric rectifiers
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hj:diva-39008 (URN)10.1515/ijeeps-2017-0114 (DOI)000425295100012 ()2-s2.0-85042112535 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Available from: 2018-03-19 Created: 2018-03-19 Last updated: 2018-09-19Bibliographically approved
Nielsen, L. P., Leisner, P. & Møller, P. (2018). Surface technology is essential for transition to a hydrogen-based energy system. Transactions of the Institute of Metal Finishing, 96(1), 8-10
Open this publication in new window or tab >>Surface technology is essential for transition to a hydrogen-based energy system
2018 (English)In: Transactions of the Institute of Metal Finishing, ISSN 0020-2967, E-ISSN 1745-9192, Vol. 96, no 1, p. 8-10Article in journal (Refereed) Published
Abstract [en]

The importance of advanced surface technology for the success of the ongoing energy turnaround in Germany has recently been discussed in this journal. The purpose of the present article is to add views based on the conditions valid for the Nordic region.

Place, publisher, year, edition, pages
Taylor & Francis, 2018
Keywords
Surfaces, Energy systems, Nordic regions, Surface technology, Metal finishing
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-38327 (URN)10.1080/00202967.2018.1403093 (DOI)000430055200005 ()2-s2.0-85038393726 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Available from: 2018-01-02 Created: 2018-01-02 Last updated: 2018-09-19Bibliographically approved
Leisner, P., Zanella, C., Belov, I., Edström, C., Sandulache, G. & Hansal, W. E. (2017). Control of silver throwing power by pulse reverse electroplating. Transactions of the Institute of Metal Finishing, 95(1), 25-30
Open this publication in new window or tab >>Control of silver throwing power by pulse reverse electroplating
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2017 (English)In: Transactions of the Institute of Metal Finishing, ISSN 0020-2967, E-ISSN 1745-9192, Vol. 95, no 1, p. 25-30Article in journal (Refereed) Published
Abstract [en]

The influence of electroplating parameters on throwing power (TP) is studied in additive-free silver cyanide solutions under direct current and pulse reverse electroplating conditions. It is found that the best TP is obtained when no agitation of the electrolyte is applied. The most important parameters for controlling the TP are the cathodic current density, the anodic to cathodic charge ratio, and the ratio between the anodic and cathodic current densities. Guidelines for process optimisation are given.

Place, publisher, year, edition, pages
Taylor & Francis, 2017
Keywords
Agitation, Pulse reverse electrodeposition, Silver, Throwing power, Electrolytes, Electroplating, Optimization, Cathodic charge, Cathodic current density, Direct current, Process optimisation, Pulse-reverse electrodeposition, Silver cyanide, Electroplating solutions
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-35017 (URN)10.1080/00202967.2017.1260895 (DOI)000394497000007 ()2-s2.0-85009956051 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Funder
VINNOVA, 2013-01883
Available from: 2017-02-06 Created: 2017-02-06 Last updated: 2018-09-19Bibliographically approved
Zhu, B., Fedel, M., Andersson, N.-E., Leisner, P., Deflorian, F. & Zanella, C. (2017). Effect of Si content and morphology on corrosion resistance of anodized cast Al-Si alloys. Journal of the Electrochemical Society, 164(7), C435-C441
Open this publication in new window or tab >>Effect of Si content and morphology on corrosion resistance of anodized cast Al-Si alloys
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2017 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 7, p. C435-C441Article in journal (Refereed) Published
Abstract [en]

This paper investigates the influence of Si content and Si particle morphology on the corrosion protection of anodized oxide layers on Al-Si alloys. Two Al alloys with low Si concentrations (2.43 wt-% and 5.45 wt-%, respectively) were studied and compared with 6082-T6 via electrochemical impedance spectroscopy (EIS) in 3 wt-% NaCl solution prior to oxide layer sealing. Si particles were also modified by the addition of Sr to study the influence of Si particle morphology on the corrosion protection of the oxide layer. The EIS showed that the corrosion protection provided by the oxide layer on Al-Si alloys is significantly affected by the presence of Si particles. Si particles make the oxide layer locally thinner and more defective in the eutectic region, thereby increasing the ease of substrate corrosion attack. However, the addition of Sr can improve the corrosion protection of anodized Al-Si alloys significantly. Furthermore, it was proved that higher Si level influences negatively the anodized oxide corrosion protection due to the higher amount of cracks and defects, but Sr modification is efficient in preventing this negative effect.

Place, publisher, year, edition, pages
The Electrochemical Society, 2017
Keywords
cast Al-Si alloys, anodising, EIS, 3D tomography
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-35095 (URN)10.1149/2.1631707jes (DOI)000404397300077 ()2-s2.0-85020855659 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Note

Part of licentiate thesis in its submitted form.

Available from: 2017-02-17 Created: 2017-02-17 Last updated: 2019-05-09Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7095-1907

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