Additive Manufacturing of Anisotropic Sm-Fe-N Nylon Bonded Permanent Magnets

Fabricating a bonded magnet with a near-net shape in suitable thermoplastic polymer binders is of paramount importance in the development of cost-effective energy technologies. In this work, anisotropic Sm2Fe17N3 (Sm-Fe-N) bonded magnets are additively printed using Sm-Fe-N anisotropic magnetic particles in a polymeric binder polyamide-12 (PA12). The anisotropic bonded permanent magnets are fabricated by Big Area Additive Manufacturing followed by post-aligned in a magnetic field. Optimal post-alignment results in an enhanced remanence of ~ 0.68 T in PA12 reflected in a parallel-oriented (aligned) measured direction. The maximum energy product achieved for the additively printed anisotropic bonded magnet of Sm-Fe-N in PA12 polymer is 78.8 KJ m-3. Our results show advanced processing flexibility of additive manufacturing for the development of Sm-Fe-N bonded magnets in polymer media designed for applications with no critical rare earth magnets.

Analysis Magnetic Properties and Corrosion Resistance of Hybrid Bonded Magnet BaFe12O19-NdFeB

Permanent Magnets made in the form of hybrid bonded BaFe12O19 / NdFeB and with binder of Poli Vynil Alcohol (PVA) as much as 3% of the total mass in each sample. The weight ratio hybride system BaFe12O19 : NdFeB is 0 % BaFe12O19 : 100 % NdFeB ; 50% BaFe12O19 : 50 % NdFeB and 70% BaFe12O19 : 30 % NdFeB. The material preparation process was begun from mixing of raw materials using HEM for 15 minutes, then added 3% wt. of PVA. The mixed powder was formed a pellet using a hydraulic press with a force of 4 tons for 1 minute, then heated with an vacuum oven at a temperature of 110 ° C for 1 hour and the last step was magnetization using impulse magnetizer. The characterization of pellet sample was done namely measurement of bulk density, flux magnetic and hysteresis loop using VSM and then measurement of corrosion resistance of hybride bonded magnet. The characterization results show that bulk density value of sample hybride 50% BaFe12O19 – 50 % NdFeB is more larger than sample hybride 70% BaFe12O19 – 30 % NdFeB , and The highest coercivity and remanence values ​​of 3900 Oe and 2500 Gauss respectively were achieved in samples with a composition of 50% Ba-ferrite - 50% NdFeB. The hybride bonded magnet Ba-ferrite/NdFeB has more corrosion resistance than bonded magnet 100 % NdFeB.

The Effect of Milling Time on Physical Properties, Magnetic Properties and Microstructure of Bonded Magnet BaFe12O19

A bonded permanent magnet of Barium hexa Ferrite has been made using powder BaFe12O19 (commercial ferrite) and a polymer of bakelite powder as binder. The composition of bakelite was varried 5% wt. The preparation of sample was begun with mass weighing for each material, then mixed together using ball mill for 1, 6 and 12 hours and using aquades as milling media. The mixed powder is dried in an oven at 110 °C for 4 hours, then the particle size distribution was measured. After that, the dried sample powder was pressed to form a pellet at pressure 40 MPa and temperature about 160 °C for 20 minutes. The characterization of sample pellet was done such as measurement of bulk density, hardness , magnetic properties using VSM and anylisis of microstructure using SEM. The results of the characterization show that the density and magnetic properties tend to increase with increasing of milling time, where the highest density, hardness and highest magnetic properties are achieved at sample with milling time for 12 hours. The value of magnetic properties at this condition are flux magnetic of 530 Gauss, remenance of 3100 Gauss, coercivity of 1,10 kOe.

Study on the Production of Bonded Magnet NdFeB and Polyvinyl Butyral

bonded magnet is composite magnet material made by mixing magnetic powder with non-magnetic binder. The process in manufacturing bonded magnet NdFeB made by mixing powder of neodymium iron boron (NdFeB) commercial type MQP-B with a polyvinyl butyral powder using a glass beaker. The comparisons of variation in composing NdFeB magnets powders with a binder of PVB (% weight) are 98:2, 96:4, 94:6 and 93:7 of 8 grams from total mass of the sample. After mixing the powder, it is molded by using a compression molding method with 8 tons pressure for 20 minutes at curing temperature 1600C. The molded samples are conducted by characterizing the physical properties which include measurement of density, microstructure analysis using SEM-EDX and magnetic properties which include measurement of the magnetic field strength using a Gaussmeter and hysteresis curve using VSM. The result of the study shows that the addition of and binder PVB in bonded magnet NdFeB causes a decrease in the density and magnetic field strength. The best result of density and magnetic field in the manufacture of bonded magnets is obtained by the addition of 2 % binder of 5.66 g/cm3 and strong magnetic field of 1862.4 G. the score of Mr = 72.86 emu/g, Ms = 103 emu/gram, Hc = 8.490 KOe and BHmax = 5.1 MGOe was obtained on the addition of PVB 2 %.