scholarly journals The Effects of Forming CeFe2 on Phase Structure and Magnetic Properties in Ce-Rich Nd-Ce-Fe-B Permanent Magnetic Materials

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6070
Author(s):  
Min Huang ◽  
Zhiqiang Qiu ◽  
Fang Wang ◽  
Hubin Luo ◽  
Changping Yang ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Grain Boundary ◽  
Magnetic Materials ◽  
Phase Structure ◽  
High Performance ◽  
Decomposition Process ◽  
Boundary Phase ◽  
Soft Phase ◽  
Negative Role ◽  
Positive Effect

The decomposition of the Nd-Ce-Fe-B phase to form CeFe2 has been usually believed to have an important positive effect on the magnetic properties of Nd-Ce-Fe-B permanent magnetic materials. In this work, a new decomposition process of the Nd-Ce-Fe-B phase on the formation of the CeFe2 phase was observed to play a negative role in its magnetic properties. It is demonstrated that the Nd-Ce-Fe-B phase decomposes into non-magnetic CeFe2, accompanied by the precipitation of Fe soft-phase. The kinks usually occurring in the demagnetization curves of Ce-rich Nd-Ce-Fe-B magnets have been determined to be related to the Fe soft-phase. Instead of using CeFe2 as a grain-boundary phase, another Ce-Cu boundary phase has been explored to efficiently improve the coercivity of Ce-rich Nd-Ce-Fe-B magnets, provided that the Ce-Cu boundary phase has an appropriate Ce to Cu ratio. The present results contribute to the mechanism comprehension and high-performance design of Nd-Ce-Fe-B permanent magnetic materials.

Grain Boundary Phase Formation and Magnetic Properties of NdFeB/Nd Multilayered Films

2009 ◽  
Vol 48 (3) ◽  
pp. 033002 ◽  
Author(s):  
Deshan Li ◽  
Shunji Suzuki ◽  
Takashi Horikawa ◽  
Masahiro Itoh ◽  
Ken-ichi Machida
Keyword(s):  
Magnetic Properties ◽  
Grain Boundary ◽  
Phase Formation ◽  
Boundary Phase ◽  
Multilayered Films

Study on the Heat–Treatment Reinforcement of Aluminum Nitride–Silicon Carbide Composites

1993 ◽  
Vol 327 ◽  
Author(s):  
Li Ningfang ◽  
Zhang Hongquan ◽  
Wang Guomei
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Silicon Carbide ◽  
Phase Composition ◽  
High Temperature ◽  
Grain Boundary ◽  
Aluminum Nitride ◽  
Phase Structure ◽  
Glass Phase ◽  
Boundary Phase

AbstractThe effects of heat – treatment on the mechanical properties of AIN – SiC whisker composites with Y2O3 and SiO2 additives has been studied. When the sample containing 10 wt% Y2O3 +SiO2 (Y2O3/SiO2= 1/0. 66) was treated at 1300°C in air for 140 hours the strength of compositqs was raised from 481 MPa to 784 MPa.The phase composition, microstructure and grain boundary phase structure have been characterized by combining XRD, SEM, TEM/EDXA and HREM techniques. The reinforcement mechanism of the composites results from crystallization of the glass phase in the grain boundary at the high temperature oxidizing atmosphere to form the crossing structure of 2Hδ Sialon fibrous phase and SiC whisker.

Effect of Aging Treatment on the Microstructures and the Magnetic Properties of the Sintered Nd-Fe-B Magnet

2014 ◽  
Vol 886 ◽  
pp. 66-70
Author(s):  
Xiao Li Wang ◽  
Li Na Zhao ◽  
Cong Hui Si ◽  
Kai Hong Ding ◽  
Sheng Li Cui ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Grain Boundary ◽  
Coercive Force ◽  
Grain Boundaries ◽  
Magnetic Phase ◽  
Aging Treatment ◽  
Experimental Results ◽  
Main Phase ◽  
Boundary Phase ◽  
Two Stage

The effect of aging processes on the microstructures and the magnetic properties of the sintered Nd-Fe-B magnet was investigated. The experimental results showed that the grain boundaries of the magnet treated by the two-stage aging processes became clear,smooth and continuous. Meanwhile, the Nd-rich grain boundary phase was precipitated at the grain boundary of the main phase to form a distinct phase separated from the main magnetic phase. The changes of the grain boundary microstructures of the sintered Nd-Fe-B magnet caused significant increase of its intrinsic coercive force.

High performance MM–FeCo–B spark plasma sintered magnets with nonmagnetic grain-boundary phase

2021 ◽  
Vol 135 ◽  
pp. 107232
Author(s):  
M. Grigoras ◽  
M. Lostun ◽  
G. Stoian ◽  
N. Lupu ◽  
F. Borza
Keyword(s):  
Grain Boundary ◽  
High Performance ◽  
Boundary Phase ◽  
Sintered Magnets ◽  
Spark Plasma

Examination of Fracture Interfaces in Silicon Nitride

1975 ◽  
Vol 33 ◽  
pp. 60-61
Author(s):  
Nancy J. Tighe
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
Crack Growth ◽  
Subcritical Crack Growth ◽  
Slow Crack Growth ◽  
Ceramic Materials ◽  
Grain Boundary Sliding ◽  
Boundary Phase ◽  
Turbine Engines ◽  
Boundary Sliding

Silicon nitride is one of the ceramic materials being considered for the components in gas turbine engines which will be exposed to temperatures of 1000 to 1400°C. Test specimens from hot-pressed billets exhibit flexural strengths of approximately 50 MN/m2 at 1000°C. However, the strength degrades rapidly to less than 20 MN/m2 at 1400°C. The strength degradition is attributed to subcritical crack growth phenomena evidenced by a stress rate dependence of the flexural strength and the stress intensity factor. This phenomena is termed slow crack growth and is associated with the onset of plastic deformation at the crack tip. Lange attributed the subcritical crack growth tb a glassy silicate grain boundary phase which decreased in viscosity with increased temperature and permitted a form of grain boundary sliding to occur.

Characterization of intergranular cuprous oxide in polycrystalline YBa2Cu3O7-x

1988 ◽  
Vol 46 ◽  
pp. 880-881
Author(s):  
Bradley L. Thiel ◽  
Chan Han R. P. ◽  
Kurosky L. C. Hutter ◽  
I. A. Aksay ◽  
Mehmet Sarikaya
Keyword(s):  
Grain Boundary ◽  
Cuprous Oxide ◽  
Room Temperature ◽  
Boundary Phase ◽  
Spectroscopic Techniques ◽  
Transition Width ◽  
Practical Applications ◽  
Thin Foils ◽  
Superconducting Oxides

The identification of extraneous phases is important in understanding of high Tc superconducting oxides. The spectroscopic techniques commonly used in determining the origin of superconductivity (such as RAMAN, XPS, AES, and EXAFS) are surface-sensitive. Hence a grain boundary phase several nanometers thick could produce irrelevant spectroscopic results and cause erroneous conclusions. The intergranular phases present a major technological consideration for practical applications. In this communication we report the identification of a Cu2O grain boundary phase which forms during the sintering of YBa2Cu3O7-x (1:2:3 compound).Samples are prepared using a mixture of Y2O3. CuO, and BaO2 powders dispersed in ethanol for complete mixing. The pellets pressed at 20,000 psi are heated to 950°C at a rate of 5°C per min, held for 1 hr, and cooled at 1°C per min to room temperature. The samples show a Tc of 91K with a transition width of 2K. In order to prevent damage, a low temperature stage is used in milling to prepare thin foils which are then observed, using a liquid nitrogen holder, in a Philips 430T at 300 kV.

Effect of Compensation and Work Environment on Employee Performance with Employee Job Satisfaction as an Intervening Variable

2018 ◽  
Vol 9 (03) ◽  
pp. 20553-20562
Author(s):  
Putu Ayu Diah Juliarti ◽  
Anak Agung Putu Agung ◽  
I Nengah Sudja
Keyword(s):  
Job Satisfaction ◽  
Work Environment ◽  
High Performance ◽  
Employee Performance ◽  
Statistical Tests ◽  
Path Coefficient ◽  
Significant Positive Effect ◽  
Organizational Goals ◽  
Record Keeping ◽  
Positive Effect

An employee who has a high performance and better able to support the achievement of the goals and objectives set by the company. Employees can work well if you have a high performance that can produce good work anyway. With the high- performance that employees, is expected to achieve organizational goals. This study examines the effect of compensation and work environment on employee performance with job satisfaction to be intervening variable. Data on compensation, work environment, job satisfaction, and employee performance obtained through observation, record keeping and questioner with respondents. The data obtained are then analyzed using Partial Least Squares (PLS). Statistical tests results showed  (1) the compensation proved significant positive effect on job satisfaction the path coefficient of 0.434 and T-Stats for 4.880, (2) work environment proved to be a significant positive effect on job satisfaction the path coefficient of 0.434 and T-Stats for 4.074, (3) job satisfaction proved to be a significant positive effect on employee performance the path coefficient of 0.264 and T-Stats for 2.458, (4) compensation proved positive and significant effect employee performance the path coefficient of 0.242 and T-Stats for 2.912, (5) work environment proved positive and significant effect employee performance the path coefficient of 0.378 and T-Stats for 3.343. Based on test results obtained statistical results of all variables positive and signicant impact.

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