Sinthesis and Characterization of Nd2Fe14B Powder from Nd-Fe-B Flakes by Wet Mechanical Milling and Heat Treatment

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.