Influence of the cooling rate on the solidification path and microstructure of a AlCoCrFeNi2.1 alloy

Autor(es)

Fernandes Oliveira, Pedro Henrique ; Siqueira Mancilha, Pedro Henrique ; Valenzuela Reyes, Rodrigo Andre ; de Gouveia, Guilherme Lisboa ; Bolfarini, Claudemiro ; Spinelli, Jose Eduardo ; Coury, Francisco Gil

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS CHARACTERIZATION; v. 203, p. 13-pg., 2023-06-29.

Resumo

The AlCoCrFeNi2.1 alloy is a promising eutectic high entropy alloy which may act as an in-situ composite, showing a trade-off between mechanical properties and ductility. Controlling the microstructure formation is crucial for achieving the best balance since it is closely related to the cooling rates during solidification. Hence, the present study determined the relationship between different cooling rates and the formed microstructures. As such, the AlCoCrFeNi2.1 alloy was subjected to a directional solidification process so that samples solidified at different cooling rates could be generated. The examined samples corresponded to a range from 1 to 6 degrees C/s, which resulted in microstructures composed of primary dendrites and uncoupled eutectic, with varying secondary dendritic spacings from 18 to 54 & mu;m and eutectic spacings from 4.5 to 10 & mu;m. The use of CALPHAD, XRD, SEM-EDS, and EBSD phase mapping enabled to determine that the primary FCC dendrites formed in all samples enveloped by the FCC + B2 eutectic. Moreover, the solidification cooling rate affected both dendritic (primary phase) and eutectic length-scales. Finally, the solidification sequence path was able to be changed, and the primary FCC dendrites were also able to form, due to the non-equilibrium nature of the solidification process, which imposed particular segregation and growth conditions. (AU)

• Processo FAPESP: 21/04302-8 - Mecanismos de refino microestrutural e otimização de propriedades mecânicas em ligas de elemento multiprincipal de alta tenacidade
• Beneficiário: Francisco Gil Coury
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 21/12589-5 - Entendendo a resistência mecânica e mecanismos de deformação de ligas CrCoNi com adições de um quarto elemento
• Beneficiário: Pedro Henrique Fernandes Oliveira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 22/02770-7 - Engenharia de Materiais Computacional Integrada ICME: aplicada à modelagem, fabricação, teste e caracterização de ligas de alta entropia
• Beneficiário: Francisco Gil Coury
• Modalidade de apoio: Auxílio à Pesquisa - Projeto Inicial