Effects of CuO content in the glass on the interfacial reaction for the NiCuZn ferrites‐FeSiCr alloy composites

Abstract

The effects of CuO content in Bi‐B‐Si‐Zn glass on the interfacial reaction between the glasses and FeSiCr alloy powder and NiCuZn ferrites, microstructure, and adhesion strength were investigated. For the FeSiCr alloy and glass interface, the iron in FeSiCr alloy dissolves into the glass and is oxidized into Fe3+ during heating. The copper ions in the glass are reduced to elemental copper near the interface to maintain charge neutrality. This leads to chemical bonding between the FeSiCr alloy and glass at 750°C under air atmosphere. The CuO in the glass increases the wettability and adhesion between the FeSiCr alloy and glass. The redox reaction inhibits crack propagation from Vickers indentations in the spherical copper‐rich precipitates near the interface, but the presence of pores in the glass layer would decrease the adhesion strength. In the FeSiCr alloy/glass/NiCuZn ferrites/glass/FeSiCr alloy structure, glass with 5 wt% CuO exhibited higher pulling strength. Moreover, the amount of elemental copper precipitates increased as the heat‐treatment temperature was increased to 800 and 850°C, leading to an increase in the glass and FeSiCr alloy adhesion strength.

Oxidation Behavior, Insulation Resistance, and Permeability of FeSiCr Alloys for Multilayer Inductors

“…Hence, it is desirable to investigate the role of oxygen partial pressure during annealing for the performance optimization of FeSiCr-based power multilayer inductors. In addition, a new concept of combining FeSiCr and Ni-Cu-Zn ferrites with Ag metallization to give a composite multilayer inductor was proposed recently [12], and annealing protocols include T and p O2 as variables as well.…”

Investigation on the micro-structure and magnetic properties of LMZBS-Bi2O3 doped low-temperature sintered NiCuZn ferrites

“…The addition of LMZBS-Bi 2 O 3 maded a greater influence on u′ than u″. It is well known that the change of permeability is caused by two kinds of magnetization mechanisms: spin rotation and magnetic domain wall motion [24,34,35]. When the NiCuZn was doped with 0.2 wt% LMZBS and 0.3 wt% Bi 2 O 3 , the highest permeability was obtained.…”