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•Some Al-Li alloys were processed by mechanical alloying.•Powder samples were sintered following two routes: HFIS and conventional.•With HFIS the refined microstructure achieved by ...milling was kept.•HFIS induced higher densification rates due porosity reduction.•The above increased the mechanical response of samples.
Al-Li alloys with different lithium contents were processed by mechanical alloying and sintered by an alternative route based on induction heating to keep the refined microstructure achieved by milling after sintering. The mechanical and microstructural features of samples sintered by a conventional route and fast induction heating were evaluated. Optical and TEM studies showed higher densification and better-refined microstructure retention after sintering using induction heating. Increased values of yield strength and hardness were obtained in the induction sintered alloys due to the porosity reduction complemented with finer microstructure.
We present the mechanical properties of all-carbon composites reinforced with in situ incorporated morphed graphene nanostructures by means of high energy ball milling and spark plasma sintering. The ...composites demonstrate enhanced elasticity for carbon sp3/sp2 ratio ≈1/4. High resolution TEM characterization and molecular dynamics simulations show that this bonding type ratio is due mostly to the morphed graphene structures. Specifically, the presence of Rh6, crosslinked graphene-like, nanostructures is attributed to the enhanced elastic properties of these all-carbon composites. The improvements in mechanical properties is approximately 2 orders of magnitude when compared to similar composites produced with graphene.
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•Equiatomic AlCoNi alloys with two added carbon allotropes were fabricated through powder metallurgy.•Graphite addition increased the hardness of the AlCoNi alloy 11%.•Different composition, ...morphology, and growth rates were observed on the oxide scale based on carbon-type addition.•CNTs benefits the formation of a protective aluminum-oxide scale instead of Ni-Co oxide.
Equiatomic AlCoNi alloys with 0.1 wt% of carbon addition in different forms such as graphite and carbon nanotubes were fabricated by powder metallurgy. The effect of carbon addition on the microstructure and oxide scale formation was investigated as a function of carbon type. Evidence showed that both carbon forms addition reduced the porosity of the sintered AlCoNi alloy. A mixture of Al and Ni-Co oxide scale was formed in all samples after a heat treatment at 1000 °C for 2 h in air. After subsequent oxidation at 900 °C for 100 h, graphite induced the Ni-Co oxide growth; meanwhile, carbon nanotubes favored the Al oxide growth. The dispersion of carbon nanotubes produced the lowest growth rate of the oxide scale.
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