Oxidation Behavior of Maraging 300 Alloy Exposed to Nitrogen/Water Vapor Atmosphere at 500 °C

Aging heat treatments in maraging steels are fundamental to achieve the excellent mechanical properties required in several industries, i.e., nuclear, automotive, etc. In this research, samples of maraging 300 alloy were aged using a novel procedure that combines different steps with two atmospheres (nitrogen and water vapor) for several hours. The oxidized surface layer was chemical, microstructural and micromechanically characterized. Due to the thermodynamic and kinetic conditions, these gases reacted and change the surface chemistry of this steel producing a thin iron-based oxide layer of a homogeneous thickness of around 500 nm. Within the aforementioned information, porosity and other microstructural defects showed a non-homogeneous oxide, mainly constituted by magnetite, nickel ferrite, cobalt ferrite, and a small amount of hematite in the more external parts of the oxide layer. In this sense, from a chemical point of view, the heat treatment under specific atmosphere allows to induce a thin magnetic layer in a mixture of iron, nickel, and cobalt spinel ferrites. On the other hand, the oxide layer presents an adhesive force 99 mN value that shows the capability for being used for tribological applications under sliding contact tests.

Synthesis and Characterization of Pure Cobalt Ferrite for DC Electrical

Ferrite Cobalt (CoFe2O4) is a distinguished magnetic material with average enforcement and average magnitude of magnetization. It has a distinct chemical stability and mechanized hardness. It is an expectant advocate for the procedure of sensory devices and actuators, as a definitive sealing, magnetic drug target, and electrical devices and has an extensive range of research in material technology/science for technological uses/applications. The naoparticles of cobalt ferrite on an entangled effectively processed at ambient temperature through a simple co-precipitation process. The crystal structure & morphology of symbol was determined by XRD and SEM. The XRD spectrum confirms that the composite nanoparticles are formed by the perfect spinel structure. The average rate of crystals was determined by means of Modified Scherer (54nm) and Williamson-Hall (49nm) methods. A SEM view showed the nanoparticles CoFe2O4 being grouped in nearby structures. The bond and visual features were described by FTIR and UV-Vis Spectrum. Compared with other absorbing bands informed in literature, this material shows a very large intake band between 350 and 600 cm-1 in the FTIR test. More than one pitch in UVVis spectrum is seen with a direct straight band gap identified of 4.1 eV and 4.9 eV. This is again in contrast to other reports in literature. These irregular outcomes express that although a very good spinel structure is in place, coordination of the symbols in the cells of the unit is different here. An electronic DC training for the temperatures cobalt ferrite was tested for temperature, which again showed some interesting results from those reported in literature. This combination of irregular buildings in considerable degree of the ferrite needs to demonstrate a deeper analysis of the overall structure and characteristics of cobalt ferrite in comparison to these methods.

Exchange bias in bismuth ferrite/cobalt ferrite Janus nanofibers

Bismuth ferrite:cobalt ferrite (BiFeO3:CoFe2O4) nanofibers with tailorable exchange bias effects were synthesized utilizing a Janus type morphology, wherein both phases are coupled longitudinally along the length of each fiber.

Modeling of Magnetoelectric Interaction in Magnetostrictive-Piezoelectric Composites

The paper dwells on the theoretical modeling of magnetoelectric (ME) effect in layered and bulk composites based on magnetostrictive and piezoelectric materials. Our analysis rests on the simultaneous solution of elastodynamic or elastostatic and electro/magnetostatic equations. The expressions for ME coefficients as the functions of material parameters and volume fractions of components are obtained. Longitudinal, transverse, and in-plane cases are considered. The use of the offered model has allowed to present the ME effect in ferrite cobalt-barium titanate, ferrite cobalt-PZT, ferrite nickel-PZT, and lanthanum strontium manganite-PZT composites adequately.