Microstructural Evolution in the Transient Solidification of Monophasic and Peritectic Sn-Sb Solder Alloys (and Sn-Sb-X) and in Solder/Substrate Interfacial Layers

• Grant number: 15/13565-1
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: September 01, 2015
• End date: November 30, 2015
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Transformation Metallurgy
• Principal Investigator: Amauri Garcia
• Grantee: José Marcelino da Silva Dias Filho
• Supervisor: Nathalie Mangelinck-Noel
• Host Institution: Faculdade de Engenharia Mecânica (FEM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: Institut Matériaux Microélectronique Nanosciences de Provence (Im2np), France
• Associated to the scholarship: 13/09267-0 - Microstructural evolution in the transient solidification of monophasic and peritectic Sn-Sb solder alloys (and Sn-Sb-X) and in solder/substrate interfacial layers, BP.DR

Abstract

Some particular metallic systems, which are characterized by invariant reactions such as eutectics, monotectics and peritectics, have been frequently investigated by the variety of microstructures that can be formed during solidification giving rise to increasingly practical applications of such alloys. With recent restrictions to the use of Pb in solder alloys, due to its toxicity, the search for alternative alloys to replace solders having Pb in their composition has increased. New compositions based on eutectic systems are being proposed with a view to replacing the classical Sn-Pb alloys, and even some peritectic compositions are being considered as potential interesting candidates. Despite the potential and interest of peritectic alloys, there is a limited comprehension of both peritectic transformation and reaction, which occur in a number of metallic binary systems. The literature gives indications that peritectic Sn-Sb alloys could be appropriate alternatives to Pb-based solders, but actually only the Sn5Sb alloy has been effectively investigated in spite of the range of potential compositions in the region of the peritectic point that deserve to be investigated, even by adding a third alloying element to their compositions. The present study aims to contribute to the investigations of lead-free solder alloys by developing a detailed analysis of the microstructural evolution of monophasic and peritectic Sn-Sb alloys as well as of ternary compositions Sn-Sb (Ag, Cu) during transient directional solidification, including the characterization of the phases forming the microstructure of solder/copper-substrate interfaces. The wettability, which is a fundamental feature of solder alloys, will be characterized for each alloy by experimental determination of the solder/substrate contact angle. Mechanical properties of the Sn-Sb alloys examined, as well as of the interfaces with copper substrates, will be determined by tensile and hardness tests.