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