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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Development of solidification microstructure and tensile mechanical properties of Sn-0.7Cu and Sn-0.7Cu-2.0Ag solders

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Author(s):
Spinelli, Jose Eduardo [1] ; Garcia, Amauri [2]
Total Authors: 2
Affiliation:
[1] Univ Fed Sao Carlos, Dept Mat Engn, BR-13565905 Sao Carlos, SP - Brazil
[2] Univ Estadual Campinas, Dept Mat Engn, BR-13083970 Campinas, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS; v. 25, n. 1, p. 478-486, JAN 2014.
Web of Science Citations: 11
Abstract

Non modified and Ag-modified eutectic Sn-0.7Cu solder alloys were directionally solidified under transient heat flow conditions. The microstructure of the Sn-0.7Cu alloy has been characterized and the present experimental results include the cell/primary dendrite arm spacing (lambda(1)) and its correlation with: the tip cooling rate () during solidification, ultimate tensile strength (sigma(u)) and elongation to fracture (delta). Distinct morphologies of intermetallic compounds have been associated with the solidification cooling rate for both alloys examined. For the Sn-0.7Cu alloy, cellular regions were observed to occur for cooling rates lower than 0.9 K/s, being characterized by aligned eutectic colonies. On the other hand, the alloy containing 2.0 wt %Ag enabled the launch of tertiary branches within the dendritic arrangement. The comparison of results allows stating that finer solder microstructures are shown to be associated with higher ultimate tensile strengths (sigma(u)) for both alloys although a more complex microstructure was found for the SAC alloy. In contrast the elongation (delta) exhibited opposite tendencies. The growth of coarse Ag3Sn fibers and platelets within interdendritic regions seems to contribute for the reduction on ductility observed for the SAC alloy. (AU)

FAPESP's process: 10/17057-7 - Experimental development of microstructure, microsegregation and tensile mechanical properties of non-ferrous alloys during upward and downward unsteady-state directional solidification
Grantee:José Eduardo Spinelli
Support Opportunities: Regular Research Grants