Combined growth of alpha-Al and Bi in a Al-Bi-Cu monotectic alloy analyzed by in situ X-ray radiography

Autor(es)

Xavier, Marcella G. C. ^[1] ; Reyes, V, Rodrigo A. ; Gomes, Leonardo F. ^[2] ; Spinelli, Jose E. ^{[3, 2]} ; Mangelinck-Noel, N. ^[4] ; Nguyen-Thi, Henri ^[4] ; Reinhart, Guillaume ^[4]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Grad Program Mat Sci & Engn, BR-13565905 Sao Carlos, SP - Brazil

^[2] Reyes, Rodrigo A., V, Univ Fed Sao Carlos, Grad Program Mat Sci & Engn, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Fed Sao Carlos, Dept Mat Engn, BR-13565905 Sao Carlos, SP - Brazil

^[4] Aix Marseille Univ, Univ Toulon, IM2NP Marseille, CNRS, Marseille - France

• Tipo de documento: Artigo Científico
• Fonte: Journal of Crystal Growth; v. 536, APR 15 2020.
• Citações Web of Science: 0

Resumo

Al-based monotectic alloys show an interesting combination of wear resistance and mechanical strength. While self-lubricating bismuth (Bi) guarantees an adequate wear resistance, the modification with copper (Cu) can increase the ability to support load. Tailoring the micromorphology of the alpha-Al phase as well as the distribution of the inclusions of Bi embedded in the alpha-Al matrix is of prime importance in order to improve the properties. In this paper, various solidification experiments are performed with the Al-3.2wt.%Bi-3wt.%Cu monotectic alloy. Real-time radiographs could be acquired during solidification by using the laboratory device SFINX (Solidification Furnace with IN situ X-radiography). The processing conditions could be chosen in such a way that both cellular and dendritic morphologies of the alpha-Al phase could be clearly seen in a single test. Micromorphological transitions from dendrites to cells are recognized for samples solidified from different cooling rates, i.e. 0.025 K/s and 0.01 K/s. Measurements of the alpha-Al dendrite velocity and growth parameters of the Bi droplets during solidification have also been extensively performed. A comprehensive model for the cellular-to-dendritic (CDT) transition of Al-based monotectic alloys is outlined. The model considers the interaction between alpha-Al and Bi droplets during solidification and its impact on the microstructure. (AU)

• Processo FAPESP: 17/12741-6 - Aplicação de técnicas experimentais de solidificação, caracterização microestrutural e de propriedades na avaliação de ligas eutéticas e hipereutéticas à base de Al e Zn
• Beneficiário: José Eduardo Spinelli
• Modalidade de apoio: Auxílio à Pesquisa - Regular