Estimation of the Maximum Carbide Size in a Hypereutectic High Chromium Cast Iron Alloyed with Titanium

Abstract

In this study, in order to obtain complete size distribution results, the maximum carbide size in a Fe-17 mass% Cr-4 mass% C hypereutectic High Chromium Cast Iron (HCCI) produced with different cooling conditions, titanium additions and heat treatment conditions was determined by using the statistics of extreme values (SEV) method. In addition, the shape factor, circularity, was estimated in order to classify the type of carbides (primary M7C3 carbides, TiC carbides and secondary M7C3 carbides). Compared to the smaller size carbides, such as TiC carbides and secondary M7C3 carbides, it was found that the slope of the extreme value distribution (EVD) regression lines is lower for the large sized carbides such as primary M7C3 carbides than for the smaller carbides. Moreover, it was found that the circularity value for the larger size carbides is higher than for the smaller carbides. Furthermore, the estimated and observed maximum carbide sizes were compared with each other for all carbide types. The characteristic of the different carbide types are summarized and classified based on the shape factor. Finally, the relationship between the carbide size distribution including the maximum carbides size and mechanical properties is discussed based on the combination of a size distribution analysis and a maximum size analysis.

Advances in Magnetic Nanoparticles for Biomedical Applications

“…Fine‐tuning of NPs' size, shape, and interparticle magnetic interaction, which determine the effective magnetic field of anisotropy, are crucial to optimize the heating efficiency of a given material to be intrinsically used for magnetic hyperthermia applications. In particular, the last significant advances to increase the SAR of iron oxide NPs were mainly based on the fabrication of nanostructures with high magnetic anisotropy (e.g., magnetite cubes, rods, and octopods) and core–shell NPs that exploit the exchange and surface anisotropy appearing when soft and hard magnetic materials are join together in one single nanostructure . However, the challenge remains since high heating power in suspension solutions may not transform into efficient heating in the cellular environment, where a drastic decrease in the SAR of colloidal nanoparticle suspensions was observed when they got into endosomes as a result of the cell internalization mechanisms.…”

Formation of strong L10-FePd/α-Fe nanocomposite magnets by visualizing efficient exchange coupling

“…The FORCs analysis results consistent with the micromagnetics model revealed that the Janus-like structure in NCMs caused the drastic decrease in H c . In other words, the NCMs largely dominated by the core/shell-like structure provided the largest (BH) max (17.5 MGOe) in the Fe-Pd system and the highest H c /H a value (26.5%) among all NCM powders, [4][5][6][7][25][26][27][28] because of the highly sensitive change of H c induced by the extremely slight transformation of phasesegregation structures. In our previous works, 4,5 we could not correctly evaluate the decrease in H c , because it was quite difficult to discuss the boundary between 'efficient' and 'inef-cient' exchange coupling between the hard and so magnetic phases by using conventional methods such as TEM, XRD and EDS elemental mapping.…”

“…4,5,[25][26][27][28] Particularly, the H c /H a value (26.5%) was also highest among all NCM powders to our knowledge, which indicates that the performance of L1 0 -FePd/a-Fe NCMs was efficiently brought out, compared with other systems. [4][5][6][7][25][26][27] To reveal which factor contributed to the high H c /H a and (BH) max , we again conducted FORCs analysis on these NCMs (Fig. 3c).…”

“…3 In many previous works, NCMs were synthesized at the necessary conditions for high performance, but their H c was much lower than the anisotropy eld (H a ), which is the H c upper limit. [4][5][6][7] Thus, to improve the H c of NCMs, we must clarify what determines their H c .…”

Oriented exchange-coupled L10-FePt/Co core-shell nanoparticles with variable Co thickness

“…Hard magnetic L1 0 -FePt nanoparticles prepared by the wet chemical method [15][16][17][18] have large magnetocrystalline anisotropy, small superparamagnetic critical size, controllable shape, catalytic activity, and can be aligned by a magnetic eld. 19,20 They are oen used as building blocks of exchange-coupled magnets such as FePt/Fe 3 Pt, 21,22 FePt/Co, [23][24][25] FePt/Fe, 26 FePt/ FeCo, 27,28 and FePt/Fe 3 O 4 . 15,23,29,30 Exchange-coupled FePt/Co core-shell nanoparticles with controllable Co thickness was prepared by Liu et al for the rst time, 23 where the introduction of the so phase increased the saturation magnetization (M s ) of the nanoparticles.…”