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Impulse Atomization of Sn-Zn and Al-Si alloys: correlations between microstructures/morphologies and processing parameters

Grant number: 16/10596-6
Support type:Scholarships abroad - Research
Effective date (Start): February 01, 2017
Effective date (End): January 31, 2018
Field of knowledge:Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
Principal Investigator:José Eduardo Spinelli
Grantee:José Eduardo Spinelli
Host: Hani Henein
Home Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
Local de pesquisa : University of Alberta, Canada  

Abstract

Rapidly solidified Sn-based solder alloys can provide metallurgical features such as low segregation and fine intermetallic compounds (IMCs). These features can be obtained in a controlled way by Impulse Atomization that provides powders of various sizes corresponding to a variety of cooling rates and undercooling levels to which diverse microstructures and morphologies are associated. Such diversity may not be obtained through conventional methods. Preliminary researches have pointed that Sn-Zn based alloys are promising alternatives to substitute solders containing lead (Pb). However, results observed for this class of alloys under fast cooling conditions remain scarce, with undermining microstructure features as a function of solidification conditions. The variation of different conditions of solidification (such as undercooling or cooling rate) gives a possibility to control the morphology and size of crystal structure, which substantially influence physical and chemical properties of alloys. In particular, deep undercooling of alloys below equilibrium liquidus, and eutectics results in rapid solidification and yields materials with improved mechanical, magnetic and electrical properties. The research group coordinated by Prof Hani Henein at the University of Alberta developed recognized expertized in the comprehension of solidification of atomized products, especially regarding the quantification of undercooling through the application of the metastable phase diagram together with eutectic fraction measured from Neutron diffraction scattering data. The present proposal includes investigations of the atomized hypereutectic Al-15 and 18wt%Si alloys with evaluation of the features in the formed microstructure, i.e., morphology and size of the eutectic Si particles and growth of a-Al halo dendrites. Recent investigations stressed that controlling size and morphology of Si particles (either eutectic or primary) - beyond the fraction of a-Al halo dendrites - may propitiate an interesting combination of mechanical properties for high content Si alloys. Both Sn-Zn and Al-Si alloys have already been investigated through transient directional solidification specimens in the framework of the project FAPESP N. 2015/11863-5: "Parâmetros da microestrutura de solidificação de ligas multicomponentes Al-Si-Cu, Sn-Bi-Sb e Zn-Sn-Cu e propriedades mecânicas decorrentes". Nevertheless, complementary studies under fast cooling are recognized as essentials with a view to complete this initiated investigation. The possibility to examine new microstructure features on these alloys would be very positive for the successful continuation of the referred project. The main objectives include detailed analysis of morphological and microstructural evolutions in as-atomized Sn-Zn and Al-Si samples alloys. So, Impulse Atomization (IA) technique will be chosen in order to explore process parameters such as type of cooling gas, overheating and large spectrum of powder sizes. (AU)

Scientific publications (7)
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
LIMA, THIAGO SOARES; SILVA, BISMARCK LUIZ; GARCIA, AMAURI; CHEUNG, NOE; SPINELLI, JOSE EDUARDO. Dendritic and eutectic growth of Sn-0.5 wt.%Cu solders with low alloying Al levels. PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS, v. 233, n. 9, p. 1733-1737, SEP 2019. Web of Science Citations: 1.
CANTE, V, MANUEL; LIMA, THIAGO S.; BRITO, CRYSTOPHER; GARCIA, AMAURI; CHEUNG, NOE; SPINELLI, JOSE E. An Alternative to the Recycling of Fe-Contaminated Al. JOURNAL OF SUSTAINABLE METALLURGY, v. 4, n. 3, p. 412-426, SEP 2018. Web of Science Citations: 1.
XAVIER, MARCELLA G. C.; SILVA, BISMARCK L.; GARCIA, AMAURI; SPINELLI, JOSE E. High Cooling Rate, Regular and Plate Like Cells in Sn-Ni Solder Alloys. ADVANCED ENGINEERING MATERIALS, v. 20, n. 7 JUL 2018. Web of Science Citations: 0.
KAKITANI, RAFAEL; REYES, RODRIGO V.; GARCIA, AMAURI; SPINELLI, JOSE E.; CHEUNG, NOE. Relationship between spacing of eutectic colonies and tensile properties of transient directionally solidified Al-Ni eutectic alloy. Journal of Alloys and Compounds, v. 733, p. 59-68, FEB 5 2018. Web of Science Citations: 14.
SPINELLI, J. E.; BOGNO, A. -A.; HENEIN, H. Two-Zone Microstructures in Al-18Si Alloy Powders. METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, v. 49A, n. 2, p. 550-562, FEB 2018. Web of Science Citations: 3.
SANTOS, WASHINGTON L. R.; CRUZ, CLARISSA B.; SPINELLI, JOSE E.; CHEUNG, NOE; GARCIA, AMAURI. Tailoring microstructure, tensile properties and fracture process via transient directional solidification of Zn-Sn alloys. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, v. 712, p. 127-132, JAN 18 2018. Web of Science Citations: 5.
SILVA, BISMARCK L.; XAVIER, MARCELLA G. C.; GARCIA, AMAMI; SPINENLLI, JOSE E. Cu and Ag additions affecting the solidification microstructure and tensile properties of Sn-Bi lead-free solder alloys. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, v. 705, p. 325-334, SEP 29 2017. Web of Science Citations: 9.

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