Aluminum carbide formation in Al-graphite composites: In situ study and effects of processing variables and sintering method

• Published in: Materials today communications Vol. 38; p. 108396
• Main Authors: Mendoza-Duarte, J.M., Estrada-Guel, I., Garcia-Herrera, J.E., Perez-Bustamante, R., Arcos-Gutiérrez, H., Martinez-García, A., Sánchez, X. Atanacio, Garay-Reyes, C.G., Carreño-Gallardo, C., Martínez-Sánchez, R.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2024
• Subjects: Aluminum carbide; Composite; Microstructure; Sintering; Aluminum carbide; Composite; Microstructure; Sintering
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2024.108396

The particulate-reinforced aluminum–matrix composites are interesting due to their attractive physical and mechanical properties over their monolithic counterparts, which are related to their prominent structural differences. The effect of interfacial reaction on the mechanical properties of the Al composites has been attributed to the influence of the reaction product. In this work, the formation of Al4C3 in Al-Gr compounds prepared by high-energy ball milling and sintered by high-frequency induction is compared with a conventional method of sintering: cold compaction and furnace sintering. The conditions related to the generation of this carbide and a precise temperature in which the initial generation of this phase occurs were determined. The different results and the in-situ characterization using HR-TEM showed the substantial reactivity of graphite in the aluminum matrix, leading to the formation of the Al4C3 phase within a few seconds of heating to 250 °C. The conventionally sintered samples displayed the highest number and size of Al4C3 precipitates. In contrast, the heated sample exhibited varied quantities and sizes of these precipitates. Notably, the high-frequency induction sintered samples contained smaller Al4C3 precipitates with a lower number density. Structural, microstructural, and chemical composition results of this phase formed in Al-Gr composites are also shown. [Display omitted] •Induction sintering generates better surface contact, improving the powder particle diffusion.•Induction sintering decreases the volumetric diffusion rate, reducing the Al4C3 growth.•Conventional sintering generates the largest grains.•Conventional sintering favors the highest density number and size of Al4C3 precipitates.•The formation and growth of Al4C3 are susceptible to the sintering method and its parameters.