• Biało, Dionizy
• Bucki, Janusz
• Skalski, Andrzej
• Paszkowski, Lech

Abstract

The work pertains to research of inhomogeneity level of the composite compacts manufactured from flaky metal particles and polymer binder. In the present investigation, magnetically hard Nd-Fe-B powders were used. The composite matrix was in all cases polystyrene. Volume fraction of the powders in composites was 40 ÷ 54%. As the forming method injection moulding was used. Granulates were obtained from powders and polystyrene dissolved with toluene. Produced cylindrical specimens had 10 mm in diameter and 4 mm in height. The structure of specimens was determined on the basis on quantitative analysis of the micrographs of axial sections. The analysis of binary images of metallographic specimens allowed to determine homogeneity and directions of flake distribution. Standard deviation of surface fraction is a measure of inhomogeneity which shows relatively well both local and general differences in the distribution of particles. The greater the volume of powder Vp in composites, the lower standard deviation S. The size of particles also influences the value of standard deviation. The greater the size of particles in a composite, the greater the values of S. In the next research, information about inhomogeneity will be useful in estimation of distribution of mechanical and magnetic parameters of the compacts (dielectromagnets) formed in this way.

Topics

• impedance spectroscopy
• surface
• polymer
• composite
• forming
• quantitative determination method