Prakt. Met. Sonderband 38 (2006) 519 
Influence of the structure on the properties of new magnetic 
composite materials 
L.A. Dobrzanski*, B. Zigbowicz*, M. Drak*, J. Konieczny* 
* Institute of Engineering Materials and Biomaterials, Silesian University of Technology, 
44-100 Gliwice, Poland 
ABSTRACT 
This paper presents the structure and its influence on magnetic properties of soft and hard 
magnetic composite materials: nanocrystalline material — polymer. For fabrication of 
composite materials the following powders were used: soft magnetic materials 
(Fe735Cu4+Nb3Si43.5Bo, CossFe4Mo+4Si43.5B13,5) and hard magnetic material 
(Nd14.8Fe76C04.95Bı.25). Composite materials were bonded by the use of (2.5 % wt.) of 
following binder: thermoplastic polyethylene, chemosetting silicone and thermosetting epoxy 
resin, respectively. Advanced composite materials were compacted by the one-sided 
uniaxial pressing. Metallographic examinations were made on the LEICA MEF4A light 
microscope equipped with the computer image analysis system. The powder grains size 
measurements were carried out on the light microscope of the magnetic materials powders. 
Observations of morphology of powders used were made on the DSM 940 OPTON 
scanning electron microscope. Examination of magnetic properties of hard magnetic 
composite materials was carried out on the MCS type device designed for examining 
permanent magnets in the magnetic circuit with the air-gap. The soft magnetic composites 
materials were examined on the Lake Shore Cryotronics Inc VSM vibratory magnetometer. 
1. INTRODUCTION 
Polymer-bonded magnetic materials are the most rapidly growing section of magnet 
market. The reasons for this rapid expansion are the requirements of market. There is also 
considerable demand for polymer-bonded magnets for small motors in video recorders, 
camcorders, printers, office automation, automotive, and portable drills. Hard and soft 
magnetic materials are fundamental to the technical success of many devices and 
products, in particular electric machines and related devices [1-3]. 
The search for the new magnetic materials has lead, among others, to development of 
research on the Fe and Co based metallic materials with the nanocrystalline structure, 
having the great soft magnetic properties and the intermetalic phases based on the rare 
earth metals and transition metals Nd-Fe-B nanocrystalline structure showing excellent 
hard magnetic properties [4, 8-10]. 
These materials are made usually as powders or thin brittle tapes which limit their range of 
applications to a great extent. Therefore, to extent their potential applications it is 
necessary to connect these powders and brittle tapes with binder. Bonding of 
Fez35CuiNb3Sii35B9, CoggFesMo4Sii35B135 andNd48Fe76C04.95B4 25 powders with the 
polymer, thermoplastic, chemically-setting and thermosetting materials or low-melting 
glasses or metals makes it possible to obtain the composite materials. These magnetic 
materials may be made also by sintering, injection moulding, hot compacting, upseting,