Resumo

CAMARILLO-CISNEROS, J.; PEREZ-BUSTAMANTE, R.  e  MARTINEZ-SANCHEZ, R.. Thermomechanical behavior of Al-Cu-Si commercial alloy modified with rare earths. Rev. mex. fis. [online]. 2020, vol.66, n.6, pp.782-789.  Epub 31-Jan-2022. ISSN 0035-001X.  https://doi.org/10.31349/revmexfis.66.782.

Microstructural and mechanical effects were studied on automotive-grade 319 aluminum alloy after cerium/lanthanum rare earth additions at room and hot working conditions. Cerium/lanthanum additions formed micrometric phases in AA319, which were stable under room and hot working conditions. In comparison with reference alloy, Ce/La doped alloys reduced the eutectic-Si up to 85%. The effect of the Ce/La addition produced an increase in hardness and UTS under room temperature while improved mechanical performance in high-temperature working conditions. These improvements were attained to the presence of well-dispersed Ce/La micrometric needles, and the amount increase of θ’-phase (Al2Cu) across the aluminum matrix. The θ’ interfered directly with crack diffusion in the solid in two crystallographic directions. Additionally, it was observed through transmission electron microscopy, that Ce/La presence altered the precipitation kinetics in the formation of the coherent θ from the θ´.

Palavras-chave : Cerium; lanthanum; aluminum.

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