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Publications (10 of 181) Show all publications
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: 2018-07-03Bibliographically 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: 2018-07-25Bibliographically 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: 2017-07-06Bibliographically 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: 2017-09-13Bibliographically approved
Péter, L., Zanella, C. & Leisner, P. (2017). European training school for young scientists and EAST Forum 2017. Transactions of the Institute of Metal Finishing, 95(5), 237-238
Open this publication in new window or tab >>European training school for young scientists and EAST Forum 2017
2017 (English)In: Transactions of the Institute of Metal Finishing, ISSN 0020-2967, E-ISSN 1745-9192, Vol. 95, no 5, p. 237-238Article in journal (Other academic) Published
Place, publisher, year, edition, pages
Taylor & Francis, 2017
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-37111 (URN)10.1080/00202967.2017.1341725 (DOI)000407570600004 ()2-s2.0-85028421094 (Scopus ID)
Note

Training Course And Conference Report

Available from: 2017-09-01 Created: 2017-09-01 Last updated: 2017-09-12Bibliographically approved
Belov, I., Nordh, A., Salomonsson, K. & Leisner, P. (2017). Fin‐Tube and Plate Heat Exchangers: Evaluation of Transient Performance. In: : . Paper presented at 18th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2017; Dresden; Germany; 3 April 2017 through 5 April 2017. IEEE
Open this publication in new window or tab >>Fin‐Tube and Plate Heat Exchangers: Evaluation of Transient Performance
2017 (English)Conference paper, Published paper (Refereed)
Abstract [en]

A methodology for evaluation of transient performance of, and comparison between plate heat exchanger and plate-fin-and-tube heat exchanger was developed and realized, including experiment and 3-D simulation. Heat transfer from water to a gas medium was addressed. The heated gas volume was the same for both heat exchanger designs. This was achieved by placing the plate-fin-and-tube heat exchanger into enclosure. The volume average temperature of the gas as function of time was computed. Estimated material cost for the studied designs was at least seven times lower than for the stainless steel plate heat exchanger. The performance of the selected plate-fin-and-tube heat exchanger design was found comparable to the plate heat exchanger, when both fin and tube materials were set to Al, and the enclosure was a light-weight thermal insulator. Transient behavior of the studied heat exchangers should be of interest for micro-grid applications, but also for thermal management in electronic cabinets and data centers.

Place, publisher, year, edition, pages
IEEE, 2017
National Category
Engineering and Technology Materials Engineering
Identifiers
urn:nbn:se:hj:diva-34638 (URN)10.1109/EuroSimE.2017.7926214 (DOI)000403217700003 ()2-s2.0-85020206472 (Scopus ID)978-1-5090-4344-6 (ISBN)978-1-5090-4343-9 (ISBN)978-1-5090-4345-3 (ISBN)
Conference
18th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2017; Dresden; Germany; 3 April 2017 through 5 April 2017
Available from: 2017-01-09 Created: 2017-01-09 Last updated: 2017-07-10Bibliographically approved
Lang, J., Belov, I., Hellén, J., Lim, J.-K., Schodt, B., Nilsson, T. M. J., . . . Leisner, P. (2017). Thermo-mechanical reliability and performance degradation of a lead-free RF power amplifier with GaN-on-SiC HEMTs. In: Materials Science Forum: . Paper presented at 11th European Conference on Silicon Carbide and Related Materials, ECSCRM 2016; Halkidiki; Greece; 25 September 2016 through 29 September 2016 (pp. 715-718). Trans Tech Publications, 897
Open this publication in new window or tab >>Thermo-mechanical reliability and performance degradation of a lead-free RF power amplifier with GaN-on-SiC HEMTs
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2017 (English)In: Materials Science Forum, Trans Tech Publications, 2017, Vol. 897, p. 715-718Conference paper, Published paper (Refereed)
Abstract [en]

RF power amplifier demonstrators containing each one GaN-on-SiC, HEMT, CHZ015AQEG, from UMS in SMD quad-flat no-leads package (QFN) were subjected to thermal cycles (TC) and power cycles (PC) followed by electrical, thermal and structural evaluation. Two types of solders i.e. Sn63Pb36Ag2 and lead-free SnAgCu (SAC305) and two types of TIM materials (NanoTIM and TgonTM 805) for PCB attachment to liquid cold plate were tested for thermomechanical reliability. Changes in electrical performance of the devices namely reduction of the current saturation value, threshold voltage shift, increase of the leakage current and degradation of the HF performance were observed as a result of an accumulated current stress during PC. No significant changes in the investigated solder or TIM materials were observed.

Place, publisher, year, edition, pages
Trans Tech Publications, 2017
Keywords
GaN (gallium nitride), HEMT (high-electron-mobility transistor), PC (power cycle), Reliability, RF (radio frequency) power amplifier, SiC (silicon carbide), TC (thermal cycle), Gallium nitride, High electron mobility transistors, Lead, Lead-free solders, Polychlorinated biphenyls, Power amplifiers, Silicon, Silicon carbide, Soldering alloys, Thermal conductivity, Thermal cycling, Threshold voltage, Tin, Electrical performance, Performance degradation, Power cycle, Radio frequencies, Thermomechanical reliability, Threshold voltage shifts, Radio frequency amplifiers
National Category
Electrical Engineering, Electronic Engineering, Information Engineering Materials Engineering
Identifiers
urn:nbn:se:hj:diva-36611 (URN)10.4028/www.scientific.net/MSF.897.715 (DOI)2-s2.0-85019987879 (Scopus ID)9783035710434 (ISBN)
Conference
11th European Conference on Silicon Carbide and Related Materials, ECSCRM 2016; Halkidiki; Greece; 25 September 2016 through 29 September 2016
Available from: 2017-07-06 Created: 2017-07-06 Last updated: 2017-07-06Bibliographically approved
Zanella, C. & Leisner, P. (2016). A critical review on the use of pulse and pulse reverse plating and their influence on electrodeposition of nanocomposite coatings. In: : . Paper presented at 7th European Pulse Plating Seminar, Vienna, March 3-4, 2016..
Open this publication in new window or tab >>A critical review on the use of pulse and pulse reverse plating and their influence on electrodeposition of nanocomposite coatings
2016 (English)Conference paper, Oral presentation only (Other academic)
Abstract [en]

Application of pulse and reverse plating to the electrodeposition of composite coatings have been adopted in the last decades but the studies were lacking in consistency of experimental approach. No major conclusion were draw on the effect of using pulse or reverse pulse plating on the codeposition of nanoparticles. Pulse plating is characterized by an increased number of variables and therefore is often difficult to understand the relationship between the parameters and the final results and compare or correlate them to available literature data. In this paper a review of major contributions in this field is carried out trying to compare results and to discuss the effect of pulse parameters on the codeposition of nanoparticles focusing on copper and nickel matrixes.

National Category
Engineering and Technology Materials Engineering
Identifiers
urn:nbn:se:hj:diva-28935 (URN)
Conference
7th European Pulse Plating Seminar, Vienna, March 3-4, 2016.
Note

Invited lecture

Available from: 2016-01-09 Created: 2016-01-09 Last updated: 2016-08-17Bibliographically approved
Zhu, B., Seifeddine, S., Persson, P. O. :., Jarfors, A. E. .., Leisner, P. & Zanella, C. (2016). A study of formation and growth of the anodised surface layer on cast Al-Si alloys based on different analytical techniques. Materials & design, 101, 254-262
Open this publication in new window or tab >>A study of formation and growth of the anodised surface layer on cast Al-Si alloys based on different analytical techniques
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2016 (English)In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 101, p. 254-262Article in journal (Refereed) Published
Abstract [en]

This paper aims to investigate the mechanisms of formation and growth of the anodised surface layer on Al-Si castings by applying different analytical techniques such as optical microscopy, scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), and X-ray computer tomography (X-ray CT) scanning. Three different Al alloys with various Si content (2.43%, 3.53% and 5.45%) were investigated. Si particle morphological modification by Sr addition, as well as directional solidification, was used to vary the microstructural coarseness in a controlled manner to study the influence of these parameters on the growth behaviour of the oxide layer. This study observed residual unanodised Al phases trapped beneath or between Si particles in the oxide layer. It was found, depending on the geometry and morphology of Si particles, that Al can be shielded by Si particles and prevented from oxidising.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Al-Si cast alloys, Anodising, Oxide layers, Silicon
National Category
Engineering and Technology Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-29789 (URN)10.1016/j.matdes.2016.04.013 (DOI)000375413100032 ()
Available from: 2016-04-18 Created: 2016-04-18 Last updated: 2018-06-08Bibliographically approved
Belov, I., Payandeh, M., Leisner, P., Jarfors, A. E. .. & Wessen, M. (2016). Effect of fillets on heat transfer in a rheocast aluminium heatsink. In: 2016 17th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE): . Paper presented at 17th International Conference IEEE EuroSimE, Montpellier, April 17-20, 2016..
Open this publication in new window or tab >>Effect of fillets on heat transfer in a rheocast aluminium heatsink
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2016 (English)In: 2016 17th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE), 2016Conference paper, Published paper (Refereed)
Abstract [en]

The effect of fillets formed between the base and plate fins of rheocast aluminium heatsinks on the thermal resistance of the heatsinks has been quantified by simulation. Simulation methodology, including sequential optimization has been developed in order to determine hotspot distributions where the fillets have the maximum effect. Combination of different fillet dimensions with various base thickness levels and aluminium alloys having inhomogeneous thermal conductivity have been investigated. For the studied cases, the effect of fillets on heatsink thermal resistance differs from negligible to 6%. The results would guide thermal designers on contribution of fillets to the heat transfer in multi-fin heatsinks for natural convection.

Keywords
Heating, Heat transfer, Metals, Conductivity, Temperature measurement, Thermal resistance
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-28920 (URN)10.1109/EuroSimE.2016.7463320 (DOI)000381743700028 ()2-s2.0-84974569543 (Scopus ID)978-1-5090-2106-2 (ISBN)
Conference
17th International Conference IEEE EuroSimE, Montpellier, April 17-20, 2016.
Available from: 2016-01-08 Created: 2016-01-08 Last updated: 2017-07-06Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7095-1907

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