Monotectic Al-Bi-Sn alloys directionally solidified: Effects of Bi content, growth rate and cooling rate on the microstructural evolution and hardness

Autor(es)

Costa, Thiago A. ^[1] ; Freitas, Emmanuelle S. ^[1] ; Dias, Marcelino ^[1] ; Brito, Crystopher ^[1] ; Cheung, Noe ^[1] ; Garcia, Amauri ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, UNICAMP, Dept Mat & Mfg Engn, BR-13083860 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Alloys and Compounds; v. 653, p. 243-254, DEC 25 2015.
• Citações Web of Science: 14

Resumo

Al-based monotectic alloys can have interesting tribological characteristics with the solute acting as a solid lubricant, while the matrix provides required structural integrity. The addition of third elements can increase the alloy load capacity. The microstructural features of these alloys, such as morphology, distribution and length scale of the phases depend strongly on the parameters of their manufacture route. In the present study monotectic Al-Bi-Sn alloys were directionally solidified (DS) under a large range of experimental cooling rates, permitting a wide spectrum of microstructural scales to be examined. Experimental correlations between the microstructure interphase spacing and solidification cooling rate and growth rate are proposed. Despite a slight increase in hardness with smaller interphase spacings for regions closer to the cooled surface of the DS alloys castings having 2 and 3.2wt.%Bi, it is shown that the Bi content of the alloy has not a significant effect on hardness. It is also shown that the experimental correlations established between the cooling rate and both the interphase spacing and area fractions of droplets of the eutectic mixture can be used in the tailoring of the microstructure of Al-Bi-Sn alloys with a view to applications in the manufacture of wear resistant components. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 13/23396-7 - Efeitos de parâmetros da microestrutura de solidificação de ligas multicomponentes à base de alumínio (Al-Mg-Si; Al-Sn-Cu; Al-Zn-Mg) nas resistências à degradação por corrosão e tribocorrosão
• Beneficiário: Amauri Garcia
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/08494-0 - Parâmetros Térmicos e Microestruturais na Solidificação Transitória de Ligas Al-Mg e Al-Mg-Si e Correlação com Resistências Mecânica e à Corrosão
• Beneficiário: Crystopher Cardoso de Brito
• Linha de fomento: Bolsas no Brasil - Doutorado
• Processo FAPESP: 14/50502-5 - Interrelation of thermal and microstructural solidification parameters and corrosion/tribocorrosion behavior of alloys for tribological, biomedical and solder applications
• Beneficiário: Amauri Garcia
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/09267-0 - Evolução microestrutural na solidificação transitória de ligas monofásicas e peritéticas Sn-Sb (e Sn-Sb-X) para soldagem e em camadas interfaciais solda/substrato
• Beneficiário: José Marcelino da Silva Dias Filho
• Linha de fomento: Bolsas no Brasil - Doutorado