Comparative Studies of Microstructure and Fatigue Life of Selected Lead-free Alloys

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Abstract

Lead-free alloys containing various amounts of zinc (4.5%, 9%, 13%) and constant copper addition (1%) were discussed. The results of microstructure examinations carried out by light microscopy (qualitative and quantitative) and by SEM were presented. In the light microscopy, a combinatorial method was used for the quantitative evaluation of microstructure. In general, this method is based on the phase quanta theory according to which every microstructure can be treated as an arrangement of phases/structural components in the matrix material. Based on this method, selected geometrical parameters of the alloy microstructure were determined. SEM examinations were based on chemical analyses carried out in microregions by EDS technique. The aim of the analyses was to identify the intermetallic phases/compounds occurring in the examined alloys. In fatigue testing, a modified low cycle fatigue test method (MLCF) was used. Its undeniable advantage is the fact that each time, using one sample only, several mechanical parameters can be estimated. As a result of structure examinations, the effect of alloying elements on the formation of intermetallic phases and compounds identified in the examined lead-free alloys was determined. In turn, the results of mechanical tests showed the effect of intermetallic phases identified in the examined alloys on their fatigue life. Some concepts and advantages of the use of the combinatorial and MLCF methods in materials research were also presented.

[1] Schmetterer, C.H., Ipser, H., Pearce, J. (2008). Lead-Free Solders: Handbook of Properties of SAC Solders and Joints, ELFNET COST 531+Lead-Free solders vol. 2. ISBN: 978-80-86292-27-4.

[2] Kroupa, A. (2012). Handbook of High-Temperature Lead-Free Solders, Volume 3: Group Project Reports. COST MP0602. ISBN: 978-80-905363-3-3.

[3] Siewert, T., Liu, S., Smith, D.R., Madeni J.C. (2002). Database for Solder Properties with Emphasis on New Lead-free Solders, Properties of Lead-Free Solders Release 4.0, National Institute of Standards and Technology, Colorado.

[4] Sobczak, N., Pietrzak, K., Kudyba, A., Nowak, R., Sobczak, J., Wojciechowski, A. (2009). Atlas of microstructures of solder alloys and solder/metal interfaces. Part 1: Optical Microscopy. Motor Transport Institute. ISBN 978-83-60965-04-07.

[5] Słupska, M., Ozga, P., Świątek, Z. & Kazimierczak, H. (2013). The development of stable baths for electrodeposition of Sn-Zn-Cu lead free solder alloys. Inżynieria Materiałowa. Volume 3, 196-199.

[6] Yassin, A. & Gomaa, E. (2015). The Study of Microstructure and Creep Properties of Cu-Doped Sn-4wt%Ag and Sn-9wt%Zn Lead Free Solders with Annealing Temperature Physics Journal. 1(2), 163-171.

[7] Kocańda, S., Szala, J. (1997). Basics of Fatigue Calculation. PWN, Warszawa. (in Polish).

[8] Mroziński, S. (2008). Stabilization of cyclic metal properties and its impact on fatigue life. Wydawnictwo Uczelniane Uniwersytetu Technologiczno-Przyrodniczego w Bydgoszczy, Rozprawy Nr 128. (in Polish).

[9] Mroziński, S. & Szala, J. (2011). Problem of cyclic hardening or softening in metals under programmed loading, Acta Mechanica et Automatica. 5(3), 99-106.

[10] Kęsy, B.K. (1990). Microstructure as arrangement of unitary phase parts and stereological parameters. Proceedings of 3rd Int. Conference on Stereology In Materials Science, Szczyrk, (pp. 226-231).

[11] Maj, M., Klasik, A., Pietrzak, K. & Rudnik, D. (2015). Modified low-cycle fatigue (LCF) test. Metalurgija = Metallurgy. 54(1), 207-210. ISSN 0543-5846.

[12] Pietrzak, K., Klasik, A., Maj, M., Wojciechowski, A. & Sobczak, N. (2017). Microstructural aspects of fatigue parameters of Sn-Zn lead-free solders with various Zn content. Archives of Foundry Engineering. 17(1), 131-136.

Archives of Foundry Engineering

The Journal of Polish Academy of Sciences

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CiteScore 2016: 0.42

SCImago Journal Rank (SJR) 2016: 0.192
Source Normalized Impact per Paper (SNIP) 2016: 0.316

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