scholarly journals The Effect of Powder Particle Biencapsulation with Ni-P Layer on Local Corrosion of Bonded Nd-(Fe,Co)-B Magnetic Material

2015 ◽  
Vol 60 (1) ◽  
pp. 153-157 ◽  
Author(s):  
D. Klimecka-Tatar ◽  
G. Pawłowska ◽  
M. Sozańska
Keyword(s):  
Magnetic Material ◽  
Epoxy Resin ◽  
Magnetic Materials ◽  
Powder Particle ◽  
Single Phase ◽  
Corrosion Behaviour ◽  
Powder Surface ◽  
Powder Particles ◽  
Individual Particles ◽  
Thermosetting Epoxy

Abstract Effect of the Nd-(Fe,Co)-B powder particle biencapsulation with Ni-P layer on bonded magnetic materials corrosion behaviour has been investigated. Bonded magnets were prepared from single-phase, nanocrystalline magnetic Nd11Fe77Co5B6 powder. Powder particles before consolidation were preliminary etched and then coated with bilayer (powder biencapsulation). The powder surface was coated as a first with autocatalytic applied Ni-P layer during 5, 15 and 30 minutes in Ni(II) containing bath and the second layer was thermosetting epoxy-resin. Impact of the used biencapsulation process was rated on the basis of polarization curves recorded in phosphate environment with addition of chloric ions. It has been established that the used biencapsulation method satisfactorily isolate individual particles of the powder and consequently, significantly inhibits corrosion processes of the final material, especially in passivating environment containing Cl-.

The Corrosion Processes Effect on Surface Roughness of Bonded Magnetic Material Based on Nd-(Fe,Co)-B Powder Type

2015 ◽  
Vol 227 ◽  
pp. 39-42 ◽  
Author(s):  
Klaudia Radomska ◽  
Grażyna Pawłowska ◽  
Dorota Klimecka-Tatar
Keyword(s):  
Surface Roughness ◽  
Epoxy Resin ◽  
Magnetic Materials ◽  
Protective Coatings ◽  
Particle Surface ◽  
Sulfate Solution ◽  
Highly Active ◽  
Before And After ◽  
Powder Particles ◽  
Powder Type

This paper presents an analysis of the Nd-(Fe,Co)-B bonded magnetic materials surface before and after corrosion tests. In the technological process of bonded magnetic materials the main difficulty is the fact that in the presence of small amounts of oxygen magnetic powders (having in their composition a highly active, a rare earth element) the particle surface easily cover with an oxide layer. The oxides phases are creating and furthermore the presence of this kind of paramagnetic phase on the powder particles surface adversely affects on the properties of the final product. Important is to protect the surface against spontaneously oxidation of the magnetic materials. One of the activities way to surface isolation is creating the additional protection coating (biencapsulation). Biencapsulation is a protection process in which not only set resin layer, but also an additional protective coating has been applied. The powder particles are coated with protective coatings: Ni-P/epoxy resin and phosphate/epoxy resin. In the paper the roughness measurement (2D) with profilometer (Taylor Hobson) results were presented. Also the effect of corrosion process evaluation on the bonded magnets surface roughness were determined (sulfate solutionpH= 3, the exposure time 4h). It has been found that the application of powder particles biencapsulation with phosphate/epoxy resin coating (in comparison with Ni-P/epoxy resin biencapsulation) leads to a more effective corrosion protection of the final bonded magnets.

Research and Design of Magnetic Substrate Microstrip Antenna with Electromagnetic Band-Gap Structure

2014 ◽  
Vol 685 ◽  
pp. 314-319
Author(s):  
Hong Yang ◽  
Dan Liu ◽  
Wei Chen
Keyword(s):  
Magnetic Material ◽  
Magnetic Materials ◽  
Microstrip Antenna ◽  
Antenna Gain ◽  
Radiation Characteristics ◽  
Relative Bandwidth ◽  
Magnetic Substrate ◽  
Gain Loss ◽  
Band Gap Structure ◽  
Research And Design

Based on the magnetic materials (JV-5) substrate, Double L-shaped slot microstrip antenna is designed. The bandwidth is over 2 times that of the normal substrate and a 40% reduction in size happens.. On this basis, the microstrip antenna with magnetic substrate EBG structure is designed and the EBG structure uses the corrosive effects of joint floor, namely getting periodic H-shaped and circular structures by the floor corrosion, and performing a simulation with HFSS14.0. The results show that the EBG structure of magnetic material having a prominent advantage of the miniaturization and bandwidth-broaden compared to a microstrip antenna with non-magnetic materials substrate, resulting in more than 10% relative bandwidth and a slight gain loss. To some degree, introducing EBG structure can reduce the size of the antenna and increase its bandwidth, and it also improve the gain and radiation characteristics of the antenna.Key words: EBG structure; magnetic material;Double L-shaped slot microstrip antenna; gain

scholarly journals Synthesis of Co(II), Ni(II) and Cu(II) Complexes from Schiff base Ligand and Reactivity Studies with Thermosetting Epoxy Resin

2011 ◽  
Vol 32 (5) ◽  
pp. 1613-1619 ◽  
Author(s):  
B. Lakshmi ◽  
K.N. Shivananda ◽  
Gouda Avaji Prakash ◽  
Krishna Reddy K. Rama ◽  
K.N. Mahendra
Keyword(s):  
Schiff Base ◽  
Epoxy Resin ◽  
Schiff Base Ligand ◽  
Thermosetting Epoxy

Manufacturing and properties of cotton and jute fabrics reinforced epoxy and PLA composites

2018 ◽  
Vol 32 (19) ◽  
pp. 1840084 ◽  
Author(s):  
Jieng-Chiang Chen ◽  
Jian-Cheng Lin
Keyword(s):  
Epoxy Resin ◽  
Brittle Failure ◽  
Natural Fiber ◽  
Woven Fabrics ◽  
Thermoplastic Composites ◽  
Composite Panels ◽  
Bending Tests ◽  
Jute Fabrics ◽  
Film Method ◽  
Thermosetting Epoxy

This paper studies the effects of plain-woven fabrics of jute and cotton, used as reinforcements, on the mechanical properties of composite panels prepared using epoxy and polylactic acid (PLA) resins as matrix materials. Two different composites were prepared in the current study — natural fiber fabrics reinforced thermosetting epoxy resin and the same fabrics reinforced thermoplastic PLA resin. Two methods were used to manufacture these composites. The thermosetting composites were manufactured by impregnating the epoxy resin with the fabrics by hand lamination. On the other hand, the resin film method was used to manufacture the thermoplastic composites. Tensile, compression and 3-point bending tests were performed on the composite panels. The experimental results indicated that the compressive strengths of cotton/PLA and cotton/epoxy composites are approximately equivalent. The jute-based composites exhibited brittle failure in the tensile test. Furthermore, the 3-point-bending break strength of the cotton/PLA composites was higher than that of the jute/PLA composites.

Influence of the Powder Particle Size on the Denudated Zone Width at Selective Laser Melting

2020 ◽  
Vol 989 ◽  
pp. 816-820
Author(s):  
Roman Sergeevich Khmyrov ◽  
R.R. Ableyeva ◽  
Tatiana Vasilievna Tarasova ◽  
A.V. Gusarov
Keyword(s):  
Particle Size ◽  
Selective Laser Melting ◽  
Powder Particle ◽  
Powder Particle Size ◽  
Adhesion Forces ◽  
Laser Melting ◽  
Friction Forces ◽  
Single Bead ◽  
Powder Particles

Mass transfer in the laser-interaction zone at selective laser melting influences the quality of the obtained material. Powder particles displacement during the formation of the single bead is experimentally studied. The so-called denudated zone was visualized by metallography. It was determined that increasing the powder particle size leads to widening the denudated zone. This can signify that the adhesion forces between powder particles prevail over the friction forces.

Liquid supercoolings and droplet cooling rates of remelted argon-atomized Fe–30Ni powder particles

1988 ◽  
Vol 3 (3) ◽  
pp. 441-452 ◽  
Author(s):  
Matthew R. Libera ◽  
Pedro P. Bolsaitis ◽  
R. Erik Spjut ◽  
John B. VanderSande
Keyword(s):  
Standard Deviation ◽  
Cooling Rate ◽  
Metal Droplet ◽  
Liquid Droplets ◽  
Interfacial Velocity ◽  
Gas Atmosphere ◽  
History Of ◽  
Powder Particles ◽  
The Difference ◽  
Individual Particles

Individual particles of argon-atomized Fe-30Ni powder are electrodynamically levitated and remelted by a CO2 laser pulse. The thermal history of each droplet during remelting and solidification is monitored by single-color radiation pyrometry at each of three wavelengths (850, 750, and 550 nm). Experiments are done in an atmosphere of either air or nitrogen. The average supercooling of six experiments performed in nitrogen is 298 K with a standard deviation of 14 K. This value is of the same order as several others reported in the literature using bulk levitation and emulsification techniques. The average supercooling of seven experiments performed in air is 163 K with a standard deviation of 20 K. The difference suggests that oxides are forming in the air-remelting experiments and catalyzing nucleation at relatively low supercoolings. The average cooling rate of the liquid droplets prior to solidification in nitrogen is 1.5 × 105 K/s. This measured cooling rate is somewhat higher than that predicted by Newtonian heat flow modeling, and the difference is attributed to radiative losses not considered in the Newtonian model. The measured cooling rate is used to estimate the total heat transfer coefficient characterizing cooling of a small metal droplet in a quiescent gas atmosphere. A lower bound of 1.5 × 106 K/s on the droplet heating rate during recalescence and a minimum average liquid/solid interfacial velocity during recalescence of 0.1 m/s are estimated.

scholarly journals Effect of curing conditions on the cutting resistance of fabrics coated with inorganic-powder-reinforced epoxy composite

RSC Advances ◽  
2020 ◽  
Vol 10 (55) ◽  
pp. 33576-33584
Author(s):  
Xuefeng Yan ◽  
Leilei Wu ◽  
Shanshan Jin ◽  
Wei Zhao ◽  
Haijian Cao ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Polyethylene Terephthalate ◽  
Epoxy Composite ◽  
Curing Process ◽  
Curing Conditions ◽  
Cutting Resistance ◽  
Thermosetting Epoxy

Inorganic powders, SiO2 and Al2O3, were used as reinforcements and thermosetting epoxy resin was utilized as a matrix to manufacture IP/epoxy preform, which was coated on the surfaces of 2/1 twill woven polyethylene terephthalate fabrics before the final curing process.

scholarly journals Electric-Field Control of Magnon Gaps in a Ferromagnet using a Spatially-Periodic Electric Field

SPIN ◽  
2017 ◽  
Vol 07 (03) ◽  
pp. 1740012 ◽  
Author(s):  
Glade Sietsema ◽  
Tianyu Liu ◽  
Michael E. Flatté
Keyword(s):  
Magnetic Material ◽  
Electric Field ◽  
Magnetic Materials ◽  
Spin Wave ◽  
Wave Dispersion ◽  
Magnetic Insulators ◽  
Periodic Electric Field ◽  
Field Control ◽  
Spatially Periodic ◽  
Propagation Properties

The frequencies and linewidths of spin waves in one-dimensional (1D) and two-dimensional (2D) periodic superlattices of magnetic materials are found, using the Landau–Lifshitz–Gilbert equations. The form of the exchange field from a surface-torque-free boundary between magnetic materials is derived, and magnetic-material combinations are identified which produce gaps in the magnonic spectrum across the entire superlattice Brillouin zone for hexagonal and square-symmetry superlattices. The magnon gaps and spin-wave dispersion properties of a uniform magnetic material under the influence of a periodic electric field are presented. Such results suggest the utility of magnetic insulators for electric-field control of spin-wave propagation properties.

Loss Separation Model: A Tool for Improvement of Soft Magnetic Materials

2016 ◽  
Vol 869 ◽  
pp. 596-601 ◽  
Author(s):  
Marcos Flavio de Campos
Keyword(s):  
Magnetic Material ◽  
Magnetic Materials ◽  
High Frequency ◽  
Eddy Currents ◽  
Soft Magnetic Materials ◽  
Barkhausen Noise ◽  
Magnetic Barkhausen Noise ◽  
Soft Magnetic ◽  
Physical Reasoning ◽  
Separation Model

Loss separation has fundamental importance for optimizing the magnetic material for a given frequency of operation. The loss separation model assumes the existence of two main terms: one due to the hysteresis at the quasi-static situation with frequency less than 0.01 Hz and another dynamic, due to high frequency eddy currents. In this study, it is discussed the physical reasoning behind the loss separation model. Magnetic Barkhausen Noise can be a valuable tool for better understanding the physics of loss separation.

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