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Published in Tom Bell, Katsuya Akamatsu, Stainless Steel 2000, 2020
Different Fe–N and Cr–N phases can be obtained directly by controlling the plasma parameters or the annealing treatment temperature. Iron nitrides such as Fe16N2, Fe4N, and Fe2–3N are attractive magnetic materials because Fe16N2 has a high saturation magnetisation Ms of 298 A m2kg−1 (Ref. 14) and Fe4N has a value of 192 A m2kg−1. Fe2−3 also has potential for application as a permanent magnetic recording medium.15
Plasma nitriding of AISI M2 steel: performance evaluation in forming tools
Published in Surface Engineering, 2020
L. H. P. Abreu, M. C. L. Pimentel, W. F. A. Borges, T. H. C. Costa, M. Naeem, J. Iqbal, R. R. M. Sousa
The sample nitrided in CPN at 400°C depicts that the intensity of base peaks are reduced, and a small quantity of iron nitride is observed. The non-appearance of intense iron nitride peaks (, ) depicts that quite thick compound layer is not established on the sample [12]. Also, this sample shows the occurrence of phase which is slightly broadened and low intense peak than base material iron peak. This is typically denoted as tetragonal nitrogen-containing martensite phase [13] or cubic ferrite phase, which contains a solid solution of nitrogen [14]. However, the sample nitrided at high temperature shows the presence of iron nitride peaks (, ), which depicts the formation of the compound layer on treated samples.
The structures and electronic properties of ferrous nitride–fulminic acid clusters
Published in Phase Transitions, 2019
Zhi Li, Zhen Zhao, Qi Wang, Tong-tong Shi
Iron nitrides are a prime candidate to electromagnets, ferrofluids and catalysts, and so on [1,2] due to the advantages such as saturation magnetization and coercivity of them [1,3]. To promote the stability and the magnetic attributes of the Fe–N ferrofluid, various long chain surfactants have been considered [4]. The surfactants also restrict the response of the ferrofluid to magnetic field [5] and even the morphology of ferrofluid nanoparticles [6]. Because surfactants, which possess polar heads, are apparently not homogeneously adsorbed on the iron nitride nanoparticles [7]. To illuminate the configurations, stability and magnetic features of iron nitride ferrofluid, we should analyze the interaction mechanisms between FeN and different surfactants. Nevertheless, the surfactants usually have larger atomic number which makes the difficulty of quantum chemical calculation unimaginable. It can be found that the fulminic acid (HCNO) is a typical molecule involving all the four elements (H,C,N,O) of the surfactants [8].
Micro-abrasive wear study of a low-temperature plasma nitrided Inconel 625 superalloy
Published in Tribology - Materials, Surfaces & Interfaces, 2022
Luis Bernardo Varela, Michell F. C. Ordoñez, Carlos Eduardo Pinedo, Andre Paulo Tschiptschin
The microstructure, microhardness, scratch resistance and micro-abrasive wear resistance of the plasma nitrided Inconel 625 were investigated. The following conclusions were derived from the results of this work. For the plasma nitrided (420 °C) specimen, the nitrogen supersaturated metastable expanded FCC is the predominant phase, but cubic nitride CrN and hexagonal iron nitride ϵ-Fe2-3N are also constituents of the nitrided layer.The low micro-abrasive wear coefficient for the nitrided sample is related to the higher hardness and nitrogen content (5.75 wt.%) of the expanded FCC phase.Mixed-mode (grooving + rolling) was observed for non-nitrided and nitrided specimens. The surface wear morphology of both specimens is consistent with the ratio S/S* (circa to 1) calculated values.The low coefficient of friction exhibited for the nitrided specimens is related to the increase in the elastic response of the nitrogen expanded austenite phase (high top surface hardness of 930 HV0.01) and the improvement in the load-bearing capacity (deduced by the HSp values), which results in lower scratch depths, minor plastic deformation and lesser piling up.The main failure mechanism observed on the nitrided layer operating during scratch was tensile cracking.