scholarly journals Fe-6.5 wt%Si Powder Cores with Low Core Loss by Optimizing Particle Size Distribution

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1699
Author(s):  
JianJun Huang ◽  
Lixin Jiao ◽  
Yu Yang ◽  
Yaqiang Dong ◽  
Yiqun Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Effective Permeability ◽  
Fine Particles ◽  
Core Loss ◽  
Eddy Current Loss ◽  
Magnetic Powder ◽  
Soft Magnetic ◽  
Separation Density

The effect of different particle size distribution of Fe-6.5 wt%Si powder on the microstructure and soft magnetic properties of the corresponding soft magnetic powder cores (SMPCs) was investigated. By optimizing particle size distribution, the density of SMPCs increased and the total core loss significantly decreased. According to the result of loss separation, density of SMPCs is inversely proportional to hysteresis loss, while with increasing the content of the fine particles, the eddy current loss significantly decreased. It was found that with magnetic powder of particle size-grading as 10%, 10%, 60%, and 20% for particles with size between −75 to +38, −38 to +23, −23 to +13, and −13 μm, respectively, the Fe-6.5 wt%Si SMPCs exhibit optimal comprehensive magnetic performances with the effective permeability of about 60, the percent permeability at 100 Oe is up to 70%, and the lowest core loss of 553 mW/cm3.

scholarly journals Properties of Fe-based nanocrystalline magnetic powder cores (MPC) and structure of particle size distribution (PSD)

2018 ◽  
Vol 69 (2) ◽  
pp. 163-169
Author(s):  
Dominik Grybos ◽  
Jacek S. Leszczynski ◽  
Marcin Kwiecień ◽  
Cezary Swieboda ◽  
Patryk Lasak ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Coarse Particles ◽  
Magnetic Powder ◽  
Mass Ratio ◽  
Soft Magnetic ◽  
Induction Components ◽  
Permeability Increase

Abstract This paper discusses the influence of the Particle Size Distribution (PSD) of the nanocrystalline Fe-based granular-soft-magnetic material on the final magnetic properties of a Magnetic Powder Core (MPC). Here we show how PSD impacts the final magnetic properties. Mixing fine and coarse particles, with a dominance of coarse particles, significantly influences the magnetic permeability increase of the core. Better magnetic features are noted for MPCs constructed with certain mass ratio of fine and coarse particles due to improvement in the magnetic path in the cores. This allows to offer new induction components to industry.

Effects of Crystal Grain Size and Particle Size on Core Loss for Fe-Si Compressed Cores

2007 ◽  
Vol 534-536 ◽  
pp. 1313-1316 ◽  
Author(s):  
Satoshi Takemoto ◽  
Takanobu Saito
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Grain Size ◽  
High Efficiency ◽  
Core Loss ◽  
Eddy Current Loss ◽  
Power Supplies ◽  
Magnetic Powder ◽  
Soft Magnetic ◽  
Treatment Conditions

Core loss of soft magnetic powder cores have been focused on to achieve high efficiency of power supplies. In this study the effects of crystal grain size on core loss were investigated by changing heat treatment conditions. It was found that core loss is influenced by crystal grain size because eddy current loss decreased and hysteresis loss increased by making crystal grain size smaller, and it is also influenced by the frequency and particle size.

The Role of Particle Size Distribution in the Performance and Modelling of Filtration

1993 ◽  
Vol 27 (10) ◽  
pp. 19-34 ◽  
Author(s):  
R. I. Mackie ◽  
R. Bai
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fine Particles ◽  
Coarse Particles ◽  
Large Particles

The paper examines the importance of size distribution of the influent suspension on the performance of deep bed filters and its significance with regard to modelling. Experiments were carried out under a variety of conditions using suspensions which were identical in every respect apart from their size distribution. The results indicate that the presence of coarse particles does increase the removal of fine particles. Deposition of fine particles leads to a greater headloss than deposition of large particles. Changes in size distribution with time and depth play an important role in determining the behaviour of a filter, and models of both removal and headloss development must take account of this.

Performance Characteristics of Centrifugal Slurry Pumps

2001 ◽  
Vol 123 (2) ◽  
pp. 271-280 ◽  
Author(s):  
B. K. Gandhi ◽  
S. N. Singh ◽  
V. Seshadri
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fine Particles ◽  
Performance Characteristics ◽  
Solid Concentration ◽  
Solid Materials ◽  
Power Characteristics ◽  
Additional Losses

The performance of two centrifugal slurry pumps has been reported for three solid materials having different particle size distribution (PSD) in terms of head, capacity, and power characteristics. The results have shown that the values of head and efficiency ratios are not only dependent on solid concentration but are also affected by PSD of the solids and properties of the slurry. The addition of fine particles in the slurry of coarser material leads to reduction in the additional losses that occur in the pumps due to the presence of solids. It is also observed that with the increase in the pump size, the additional losses due to presence of solids reduce.

Particle Size Distribution Measurement of Free-Falling Fine Particles in a Dusty Plasma Experiment

2001 ◽  
Vol 40 (Part 1, No. 5A) ◽  
pp. 3433-3434
Author(s):  
Nobuki Kawashima ◽  
Kazuya Takeda ◽  
Takeharu Etoh ◽  
Kousei Takehara ◽  
Haruya Kubo ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Dusty Plasma ◽  
Fine Particles ◽  
Distribution Measurement ◽  
Plasma Experiment ◽  
Particle Size Distribution Measurement ◽  
Free Falling

MPT Influence on the Rheological Behaviour of Self-Flow Refractory Castables

2008 ◽  
Vol 587-588 ◽  
pp. 133-137 ◽  
Author(s):  
Abílio P. Silva ◽  
Ana M. Segadães ◽  
Tessaleno C. Devezas
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Mechanical Strength ◽  
Size Distribution ◽  
Fine Particles ◽  
Rheological Behaviour ◽  
Response Surfaces ◽  
Coarse Particles ◽  
Aggregate Particle ◽  
Refractory Castables

The success of a refractory castable is largely due to the quality of its properties and ease of application. Self-flow refractory castables (SFRC), with high flowability index (>130%), can be easily accommodated in a mould without the application of external energy, being ideal for the manufacture of monolithic linings. SFRC castables without cement require a matrix of very fine particles, which guarantees improved rheological behaviour and performs the role of the binder in the absence of the refractory cement. The presence of the aggregate (coarse particles) hinders the flowability index, but improves the castable mechanical strength and reduces firing shrinkage, and also contributes to the reduction of the castable costs. The control of the maximum paste thickness (MPT) allows the reduction of the coarse particles interference, minimizing the number of contact points among the grains and avoiding the formation of an aggregate skeleton that impairs the flowability of the mixture. In the present work, 100% alumina SFRCs without cement were produced with a fixed matrix of fine particles, whose particle size distribution was optimized using statistical techniques (mixtures design and triangular response surfaces). Different aggregate particle size distributions were used, with several MPT values, with the objective of evaluating which was the mean distance that maximized the flowability index, simultaneously ensuring good mechanical strength for the refractory castable. Ensuring a minimum surface area of 2.22m2/g, the mixtures reach the self-flow turning point with a minimum water content and the maximum flowability is obtained for an aggregate particle size distribution modulus of q=0.22, and consequently an optimized MPT value. SFRC with high mechanical strength (>60MPa) were obtained.

scholarly journals Size Characteristics of Sediments Eroded under Different Masson Pine Litter Covers in South China

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2190
Author(s):  
Fangfang Zhu ◽  
Yuchen Li ◽  
Jinhua Cheng
Keyword(s):  
Particle Size ◽  
Soil Erosion ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fine Particles ◽  
Enrichment Ratio ◽  
Coarse Particles ◽  
Characteristic Parameters ◽  
Sediment Distribution ◽  
The Relationship

The particle size distribution characteristics of runoff sediments are vital for understanding the effect of the mechanism of soil erosion on slopes. The objective of this study was to investigate the particle-size distribution of sediments eroded from slopes covered by different litter coverage masses under artificial rainfall simulation. Litter was spread on the surface of a soil tank according to different biomasses (0 g·m−2, 100 g·m−2, 200 g·m−2 and 400 g·m−2). The mean weight diameter (MWD), fractal dimension (D) and enrichment ratio (ER) are characteristic parameters of sediment particle size. The MWD and D were more sensitive to soil erosion and had a significant negative correlation with the slope angle and rainfall intensity. The performance of the MWD on the slope (5°) was less than the MWD on the slope (10°). The relationship between eroded sediment distribution characteristic parameters and the litter coverage mass had a significant influence on the content of coarse particles. The content of fine particles accelerated, decreased and then stabilized, whereas coarse particles increased first and then stabilized. The litter diameter and surface area were the main parameters that affected the MWD and D. Under different rain intensities and slopes, the ER varied inconsistently with litter coverage mass. Coarse particles were eroded easily and selectively, and soil erosion had no sorting effect on fine particles. These findings support the quantitative study of the relationship between the amount of litter coverage mass and the particle size of soil sediments.

Influence of particle-size distribution homogeneity on shearing of soils subjected to internal erosion

2020 ◽  
Vol 57 (11) ◽  
pp. 1684-1694
Author(s):  
Shijin Li ◽  
Adrian R. Russell ◽  
David Muir Wood
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Soil Sample ◽  
Size Distribution ◽  
Fine Particles ◽  
Internal Erosion ◽  
Triaxial Tests ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Homogeneous Particle

Internal erosion (suffusion) is caused by water seeping through the matrix of coarse soil and progressively transporting out fine particles. The mechanical strength and stress–strain behavior of soils within water-retaining structures may be affected by internal erosion. Some researchers have set out to conduct triaxial erosion tests to study the mechanical consequences of erosion. Prior to conducting a triaxial test they subject a soil sample, which has an initially homogeneous particle-size distribution and density throughout, to erosion by causing water to enter one end of a sample and wash fine particles out the other. The erosion and movement of particles causes heterogeneous particle-size distributions to develop along the sample length. In this paper, a new soil sample formation procedure is presented that results in homogeneous particle-size distributions along the length of an eroded sample. Triaxial tests are conducted on homogeneous samples formed using the new procedure as well as heterogeneous samples created by the more commonly used approach. Results show that samples with homogeneous post-erosion particle-size distributions exhibit slightly higher peak deviator stresses than those that were heterogeneous. The results highlight the importance of ensuring homogeneity of post-erosion particle-size distributions when assessing the mechanical consequences of erosion. Forming samples using the new procedure enables the sample’s response to triaxial loading to be interpreted against a measure of its initially homogenous state.

Nearfield development of the negatively buoyant Rhône River inflow into Lake Geneva as an interflow: suspended particulate matter and associated fluxes.

2021 ◽  
Author(s):  
Violaine Piton ◽  
Frédéric Soulignac ◽  
Ulrich Lemmin ◽  
Graf Benjamin ◽  
Htet Kyi Wynn ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Suspended Particulate Matter ◽  
Fine Particles ◽  
River Plume ◽  
Lake Geneva ◽  
Suspended Particulate ◽  
Negatively Buoyant

<p>River inflows have a major influence on lake water quality through their input of sediments, nutrients and contaminants. It is therefore essential to determine their pathways, their mixing with ambient waters and the amount and type of Suspended Particulate Matter (SPM) they carry. Two field campaigns during the stratified period took place in Lake Geneva, Switzerland, in the vicinity of the Rhône River plume, at high and intermediate river discharge. Currents, water and sediment fluxes, temperature, turbidity and particle size distribution were measured along three circular transects located at 400, 800 and 1500 m in front of the river mouth. During the surveys, the lake was thermally stratified, the negatively buoyant Rhône River plume plunged and intruded into the metalimnion as an interflow and flowed out in the streamwise direction. Along the pathway, interflow core velocities, SPM concentrations and volumes of particles progressively decreased with the distance from the mouth (by 2-3 times), while interflow cross sections and plume volume increased by 2-3 times due to entrainment of ambient water. The characteristics of the river outflow determined the characteristics of the interflows: i.e. interflow fluxes and concentrations were the highest at high discharge. Both sediment settling and interflow dilution contributed to the observed decrease of sediment discharge with distance from the mouth. The particle size distribution of the interflow was dominated by fine particles (<32 μm), which were transported up to 1500 m away from the mouth and most likely beyond, while large particles (>62 μm) have almost completely settled out before reaching 1500 m. </p>

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