| Autor: |
Martínez C; Departamento de Ingeniería de Obras Civiles, Universidad de La Frontera, Temuco 4811230, Chile., Arcos C; Departamento de Ingeniería Mecánica y Metalúrgica, Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile., Briones F; Escuela de Mecánica, Pontificia Universidad Católica de Valparaíso, Quilpué 2430120, Chile., Machado I; Departamento de Engenharia Mecatrônica e Sistemas Mecânicos, Escola Politecnica, Universidade de São Paulo, São Paulo 05508-030, Brazil., Sancy M; Escuela de Construcción Civil, Facultad de Ingeniería, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile., Bustamante M; Departamento de Ingeniería de Obras Civiles, Universidad de La Frontera, Temuco 4811230, Chile. |
| Abstrakt: |
This work presents the effect of CeO 2 nanoparticles (CeO 2 -NPs) on Cu-50Ni-5Al alloys on morphological, microstructural, degradation, and electrochemical behavior at high temperatures. The samples obtained by mechanical alloying and spark plasma sintering were exposed to a molten eutectic mixture of Li 2 CO 3 -K 2 CO 3 for 504 h. The degradation of the materials was analyzed using gravimetry measurements and electrochemical impedance spectroscopy. Different characterization techniques, such as X-ray diffraction and scanning electron microscopy, were used to investigate the phase composition, parameter lattice, and microstructure of Cu-Ni-Al alloys reinforced with CeO 2 -NPs. The hardness of the composite was also examined using the Vickers hardness test. Gravimetry measurements revealed that the sample with 1 wt.% CeO 2 -NPs presented the best response to degradation with a less drastic mass variation. Impedance analysis also revealed that by adding 1 wt.% CeO 2 -NPs, the impedance modulus increased, which is related to a lower porosity of the oxide film or a thicker oxide layer. The microhardness also significantly increased, incorporating 1 wt.% CeO 2 -NPs, which reduced with higher CeO 2 -NPs content, which is possibly associated with a more uniform distribution using 1 wt.% CeO 2 -NPs in the Cu-Ni-Al matrix that avoided the aggregation phenomenon. |
