Preparation and characterization of bakelite bonded magnet NdFeB used for electric generator

Abstract

Abstract The permanent magnets based on NdFeB is well known as rare earth alloy magnets made from neodymium, iron and boron elements and has tetragonal crystalline structure Nd2Fe14B which has high coercivity, large energy product (app 50 MGOe) and curie temperature about 312 °C. In this paper will be discussed the preparation of bakelite bonded magnet NdFeB and characterization, also the purpose of this research is to make bonded magnet NdFeB using 3 % bakelite and know the extent to which can be applied in making a small electric generator. The bonded magnet NdFeB was made by mixing a magnetic powder NdFeB with a polymer as binder. The composition of the sample consisted of 97 wt. % of NdFeB powder and 3 wt.% of bakelite. The mixed raw materials were then pressed to form a disc with pressure about 40 MPa at temperature about 160 °C for 20 minutes. It was obtained a disc with size 40 x 18 x 6 mm. The disc samples were magnetized by using impulse magnetizer at 1500 Volt DC, then the samples were measured magnetic properties by using Gauss meter and Permeagraph. The measurements result show that, the bakelite bonded magnet NdFeB has Magnetic Flux = 1100 Gauss, Remanence Br = 5.20 kGauss, Coercivity Hc = 6.14 kOe and Energy product (BH) max = 4.78 MGOe. The bonded magnet NdFeB was applied to the prototype small generator with single rotor and single stator. The results of performance test of generator indicate that it is achieved output power of generator about 9.98 Watt at a maximum speed about 500 rpm.