Hybrid bonded magnet Ba-Ferrite/NdFeB with 5% wt Epoxy Resin (ER) as polymer binder hsa been developed with variations in BaFe12O19 to NdFeB weight ratio. The variation of the BaO6Fe2O3 : Nd-Fe-B weight ratio are 90%:10%; 80%:20%; 70%:30% and 60%:40%. The magnetic particle consist of Ba-Ferrite and NdFeB were mixed until homogenize and compacted by using hydraulic press machine with 8 Tonf force to form a disc shape sample. The disc sample was dried using vacuum dryer with 10 mm bar pressure at 80°C for one hour before being magnetized using impulse magnetizer. The best %wt composition ratio of Ba-Ferrite/NdFeB is 70%/30% and 60%/40%. The hybrid bonded magnetic properties at the best %wt composition ratio are: bulk density = 4.28-4.43 g/cm3, FM = 1057-1121 Gauss, Br = 3.46-3.70 kG, Hc = 3.25-3.70 kOe, and BHmax = 1.60-1.70 MGOe.

Abstract. The purpose of this experiment is to analyze the influence of sintering temperature to the microstructure, physical, and magnetic properties of BaFe 12 O 19 materials. The permanent magnet BaFe 12 O 19 was made by using milling and sintering method, BaFe 12 O 19 commercial powder was used as the raw material in this experiment. The raw material was pulverized by using ball mill for 15 hours and compacted at 400 MPa pressure to obtain a 16mm diameter and 4mm thick pellet. The pellet was sintered with 10 o

The Nyodimium-Iron-Boron (Nd-Fe-B) based materials are known as the best type of magnetic materials and it contains a magnetic phase Nd2Fe14B. The Nd-Fe-B alloy Flakes is one of the main raw material for producing of NdFeB-based permanent magnets and the size of Nd-Fe-B flakes are still coarse. Synthesis of Nd2Fe14B powder has been done by a wet mechanical milling method using the High Energy Milling (HEM) for 10 hrs and continued by heating at 600°C in vacuum condition (10-4 Pa). This process is used to produce a fine powder Nd2Fe14B for making of permanent magnets. The milling medium was used a toluene (pa-Emerck)) to protect of particle from oxidation during the milling process. After milling processes, the samples were measured distribution particle size by using Particle Size Analyzer (PSA). Microstructure analysis has been conducted by using X-ray diffractometer (XRD) and Scanning Electron Microscope (SEM/EDX) for samples before milling and sample after heating. The characterization results show that after milling 10 hours, it was obtained fine powder with average size about 1.35 μm. According to SEM/EDX and XRD analysis show that the crystal structure of the sample before milling was different compared to the sample after heating. It is found new magnetic phase with formula Nd2Fe14B.

No abstract

A spark plasma sintering technique was used to consolidate NdFeB compacts at four different temperatures as 750°C, 850°C, 950°C and 1030°C. The surface of specimens was polished to remove the carbon paper on the surface of NdFeB compacts by using SiC paper for up to #1500 in grit. The polished NdFeB compacts were then magnetized by using impulse magnetizer K-series. In this study, the effects of temperature on the structure and magnetic properties of NdFeB magnet were studied. The results show that depending on the fabrication temperature, the X-ray diffraction patterns of NdFeB compacts are distinct. This suggests that the structure of NdFeB compacts is changed with increase in fabrication temperature. Meanwhile, the remanance Br and energy product BH(max) of NdFeB magnets tend to decrease as fabrication temperature increase.