Busca avançada
Ano de início
Entree
(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Sn-Mg lead-free solder alloy: Effect of solidification thermal parameters on microstructural features and microhardness

Texto completo
Autor(es):
da Cruz, Clarissa B. [1] ; Lima, Thiago S. [1] ; Costa, Thiago A. [2] ; Brito, Crystopher [3] ; Garcia, Amauri [1] ; Cheung, Noe [1]
Número total de Autores: 6
Afiliação do(s) autor(es):
[1] Univ Estadual Campinas, UNICAMP, Dept Mfg & Mat Engn, BR-13083860 Campinas, SP - Brazil
[2] IFPA, Fed Inst Educ Sci & Technol Para, BR-66093020 Belem, Para - Brazil
[3] Sao Paulo State Univ, UNESP, Campus Sao Joao da Boa Vista, BR-13876750 Sao Joao Da Boa Vista - Brazil
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: MATERIALS RESEARCH EXPRESS; v. 6, n. 12 DEC 2019.
Citações Web of Science: 0
Resumo

In the last decade, several studies have been developed on lead-free alloys as potential candidates to replace Sn?Pb alloys in soldering processes. Sn?Mg alloys arise as promising alternatives due to characteristics such as low melting point, low coefficient of thermal expansion, suitable mechanical properties, electrical resistivity and low cost of Mg as an alloying element. However, the literature is scarce on studies relating the microstructure features of unsteady state cooling conditions during solidification to the resulting properties of Sn?Mg alloys. It is of the utmost importance to know the influence of the solidification cooling rate on the representative length scale of the alloy microstructure, since it varies from about 0.4 to 8 ;C s(?1) in the soldering process. In the present study the Sn 2.1 wt%Mg eutectic alloy is solidified under unsteady state conditions over a nickel substrate for a range of solidification cooling rates from 0.5 to 12 ;C s(?1). The microstructure is shown to be formed by a mixture of ??Sn and fibrous Mg2Sn intermetallics (IMC) and an experimental growth law is proposed relating the interphase spacing between Mg2Sn fibers (?(F)) and the cooling rate. With the decrease in the cooling rate a pronounced decrease in the Mg2Sn IMC fraction is shown to occur; from about 46% to 23%. Consequently, hardness, that is shown to depend on both ?(F) and Mg2Sn fraction, decreases significantly with the decrease in the solidification cooling rate. (AU)

Processo FAPESP: 17/15158-0 - Caracterização microestrutural e de propriedades na avaliação de ligas para contato térmico interfacial
Beneficiário:Amauri Garcia
Linha de fomento: Auxílio à Pesquisa - Regular