scholarly journals Effects of Static Magnetic Field on Compression Properties of Mg-Al-Gd Alloys Containing Gd-Rich Ferromagnetic Phase

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4957
Author(s):  
Qi Cai ◽  
Xinyao Li ◽  
Shukui Li ◽  
Chuan He ◽  
Xingwei Liu ◽  
...  

The Mg–0.6Al–20.8Gd (wt.%) alloys were homogenized at 620 °C for 20 min under 0 T and 1 T, followed by furnace cooling, quenching, and air cooling, respectively. The effects of the magnetic field on the phase constituent, microstructure, secondary phase precipitation, and mechanical properties of the Mg–Al–Gd alloys were investigated. The Mg–Al–Gd alloys contained α-Mg, Mg5Gd, Al2Gd, and GdH2 phases, and the phase constituents were hardly influenced by the applied magnetic field. However, the precipitation of the paramagnetic Mg5Gd upon cooling was accelerated by the magnetic field, and that of the ferromagnetic Al2Gd phases was inhibited. In addition, the Al2Gd phase was significantly refined and driven to segregate at the grain boundaries by the magnetic field, and the resultant pinning effect led to the microstructure change from dendritic α-Mg grains to rosette-like ones. When the magnetic field was only applied to the homogenization stage, the content of the Mg5Gd phase remained unchanged in the quenched alloy, whereas the Mg5Gd laths were significantly refined. By contrast, the contents of the Al2Gd and GdH2 phases were increased, while the precipitation sites were still within the α-Mg grains. The Mg5Gd laths were incapable of providing precipitation strengthening, while the Al2Gd and GdH2 particles brought positive effects on the enhancement of the mechanical properties. In the quenching condition, the hardness, compression strength, and ductility can be improved by the magnetic treatment, whereas these mechanical properties can be suppressed in the furnace cooled condition by the magnetic treatment.

2018 ◽  
Vol 55 (3) ◽  
pp. 442-446
Author(s):  
Carmen Penelopi Papadatu ◽  
Andrei Victor Sandu ◽  
Marian Bordei ◽  
Ioan Gabriel Sandu ◽  
Sorin Ciortan

The article focuses on the behavior of the non-conventional treated alloyed steel in magnetic field, during the dry wear tests. It is a review of the experimental tests from last years. The thermo-magnetic treatments have been applied before the application of a thermo-chemical treatment in plasma based on diffusion process. The study was made in order to improve the mechanical properties of the alloyed steel during the friction wear. Thermo-magnetic treatment applied before the plasma nitro-carburizing treatment improves the mechanical properties of the material especially in this case, for a steel that has a considerable content of Chromium (1.02%). The behavior was studied using X-Ray diffractometry of the superficial layers during the dry friction of wear process. The wear tests used an Amsler machine, during three hours of wear tests. After each hour of the wear tests the samples have been analyzed. The diffractometric characteristics of the superficial layers obtained after a complex array of thermo-magnetic and thermo-chemical in plasma treatments, the phases distribution, the content of the superficial layers and the behavior of the steel during the wear through dry friction tests, have been considered as criteria.


2013 ◽  
Vol 10 (1) ◽  
pp. 73-84
Author(s):  
Baghdad Science Journal

Permanent magnets of different intensities were used to investigate the effect of a magnetic field in the process of preventing deposits of calcium carbonate. The magnets were fixed on the water line from the tap outside. Then heating a sample of this water in flasks and measuring the amount of sediment in a manner weighted differences. These experiments comprise to the change of the velocity of water flow, which amounted to (0.5, 0.75, 1) m/sec through the magnetic fields that are of magnetic strength (2200, 6000, 9250, 11000) Gauss, and conduct measurements, tests and compare them with those obtained from the use of ordinary water.The results showed the effectiveness of magnetic treatment in reducing the rate of deposition of calcium carbonate where up to 60% after treatment, and this percentage is increasing with increasing magnetic field strength where up to 85% when the intensity of the magnetic field 9250 and 11000 Gauss at the velocity of the water flow of 0.75 m/sec. This percentage of reducing was investigated with increasing the velocity of flow of water through a magnetic field. Also the results showed an increase in total dissolved solids (TDS) as well as electrical conductivity and a decrease in the value of surface tension as a result of magnetic treatment.Observation with the photograph pictures of the distillation apparatus oriented in several laboratories, that the amount of sediment formed a thick layer in the device-free magnetic treatment, but it was not dense and in the few quantity in the apparatus treated with magnetic intensity (8000, 9250) Gauss.


Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 714 ◽  
Author(s):  
Anderson Vergílio de Queiroz ◽  
Márcio Teodoro Fernandes ◽  
Leonardo Silva ◽  
Rudineli Demarque ◽  
Carlos Roberto Xavier ◽  
...  

Welding is a widely used process that requires continuous developments to meet new application demands of mechanical projects under severe conditions. The homogeneity of metallurgical and mechanical properties in welded joints is the key factor for any welding process. The applications of external magnetic fields, mechanical vibration, and ultrasound are the fundamental steps to achieve success in improving these properties. The present work aimed at determining suitable processing conditions to achieve the desired balance between metallurgical and mechanical properties of 304L steel in TIG (Tungsten Inert Gas) welding under the application of an external magnetic field. The microstructural characteristics of the weld bead were analyzed by optical microscopy (OM) and scanning electron microscopy (SEM). In order to evaluate the mechanical properties of the welded specimen, its Vickers microhardness map and Charpy impact energy at −20 °C were obtained. In addition, corrosion tests were carried out in the saline medium to compare the corrosion resistance of the joint with that of the base metal and that without the magnetic field. It was found that the external magnetic field decreased the percentage of delta ferrite, improved the filling of the weld pool with the weld metal, and decreased the primary and secondary dendritic spacings. The Vickers microhardness value under the magnetic field was found to be lower than that without the magnetic field, and the Charpy test showed no significant variation in energy absorption. Moreover, the welded joint produced under the external magnetic field manifested less resistance to corrosion.


2016 ◽  
Vol 251 ◽  
pp. 3-7 ◽  
Author(s):  
Egidijus Dragašius ◽  
Evguenia Korobko ◽  
Zoya Novikava ◽  
Elena Sermyazhko

Mechanical properties of polymer composite materials, containing ferromagnetic small dispersed particles of carbonyl iron that create structures along force lines of the magnetic field have been investigated. In paper the influence of the polymer matrix material and the orientation of ferromagnetic particles inside it on the properties of polymer composites are considered in the regimes of horizontal shear, vertical shear and periodical (sinusoidal) deformation of the samples. Magnetic properties at the change of magnetic field induction B in the range of 0 to 1 T are determined.


2012 ◽  
Vol 26 (4) ◽  
pp. 375-380 ◽  
Author(s):  
Y. Jamil ◽  
Zia ul Haq ◽  
M. Iqbal ◽  
T. Perveen ◽  
N. Amin

Abstract The magnetic treatment effects on mushroom spawn growth and yield were studied. The spawn of mushroom were exposed to full-wave rectified sinusoidal magnetic field. The spawn were grown after magnetic field treatment under controlled laboratory conditions. The magnetic field treatment resulted in significant increase (P<0.05) in the growth and yield of mushroom. The number of pin heads formed, number of pin heads developed into mature mushrooms, fresh (wet) and dry masses increased up to 38.18, 34.83, 76.43, and 38.26%, respectively, while reduction in number of days for spawn complete running and number of days for appearance of pin heads was found to be -3.14 and -26.86%, respectively.


2020 ◽  
Vol 87 (8) ◽  
Author(s):  
Ali Shademani ◽  
Mu Chiao

Abstract Magnetic elastomers (MEs) respond to an applied magnetic field through magnetomechanical coupling, where the mechanical properties of the MEs change with magnetic field strength. These phenomena have been mostly studied under homogenous magnetic fields due to the simplicity. In this work, the effects of the magnetic field gradient on the mechanical properties and the response of the MEs was examined. MEs are made by embedding carbonyl iron microparticles (CI) into a polydimethylsiloxane (PDMS) matrix, which is later rendered porous. The influence of the CI concentration was investigated by manipulating four different samples with CI/PDMS weight ratios of 0.2, 0.6, 1.0, and 1.4. An analytical method was proposed to further understand the interactions of the magnetic field gradient and the material’s response. The proposed theory was later verified with experimental results from compression tests in the presence of different magnetic fields. The proposed theoretical framework and experimental methods can be used to improve the design of MEs in the future.


2019 ◽  
Vol 121 ◽  
pp. 02006 ◽  
Author(s):  
I.A. Golubev ◽  
A.B. Laptev ◽  
E.L Alekseeva ◽  
N.O. Shaposhnikov ◽  
A.M. Povyshev ◽  
...  

The article considers the possibility of increasing the efficiency of chemical reagents by treating inhibited solutions with a magnetic field. It is shown that a various method for generating the magnetic field has a different effect (Some positive some negative). The best results can be achieved with anti-scale magnetic treatment using permanent magnets. Modified inhibitors (after magnetic treatment) have enhanced protective effectby their adsorption capacity with respect to metal increases.


2013 ◽  
Vol 772 ◽  
pp. 83-88
Author(s):  
Ning Zhu ◽  
Ya Jie Liu

The resistance associated with temperature and magnetic field is a crucial parameter in researching the physical properties of the Perovskite-type manganites. To find out a suitable method to predicting the resistance of La0.65Ca0.35MnO3and La0.8Sr0.2MnO3in the process from paramagnetic phase to the ferromagnetic phase via the temperature and the magnetic field was the aim of this paper. By the nonlinear fitting, an appreciated analytic expression showing the temperature-dependence resistance both less or higher than the metal-insulator transition temperature,Tc, at different magnetic field was put forward. All of the nonlinear fitting between the measured and the calculated data were so satisfied that the minimum correlation coefficient is below 0.9997, the average relative errors do not exceed 1.0%.


2015 ◽  
Vol 1095 ◽  
pp. 483-489
Author(s):  
Kwang Hee Lee ◽  
Kyung Sik Jung ◽  
Chul Hee Lee

This study examines the relation between the thickness of a specimen and the weight of an impactor for evaluating the shock absorption performance of magneto-rheological (MR) elastomers with and without a magnetic field. The shock absorption performance can be evaluated by calculating impact energy. The MR elastomer is a smart material and its mechanical properties change under the influence of a magnetic field. The drop impact test is performed to evaluate the amount of shock absorption of the MR elastomer for each test condition. Tests are also performed by varying the magnetic field during impact to improve the shock absorption performance of the MR elastomer, which is related to impact load. The results show a better shock absorption performance with a thicker MR elastomer, lighter impactor, and without a magnetic field. Also, the magnitude of impact and the time duration for stabilization are improved when the magnetic field is varied during the test.


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