Ferrite Core Composition for Heat-Resistant Wire-Wound Coils
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Solution Overview
Problem
Ferrite sintered bodies used in wire-wound coil devices often lack sufficient heat resistance, leading to compromised thermal shock resistance in the final coil products.
Innovation Solution
A ferrite sintered body composition with specific ranges of Fe, Cu, Ni, Zn, B, and Nb, along with optional Mo, is developed to enhance flexural strength, magnetic permeability, and Curie temperature, which is then used as a ceramic core in a wire-wound coil component.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ferrite materials (Ni-Zn or Mn-Zn based) are used for the drum core, then the coil device can be manufactured, but the thermal shock resistance is insufficient
Solution Approach 1:
The patent changes the chemical composition parameters of the ferrite material by adding specific amounts of CuO (2-8 mol%), NiO (12-19 mol%), ZnO (28.5-33 mol%), Fe2O3 (48.2-49.7 mol%), along with B (5-25 ppm) and Nb (6-25 ppm). This parameter optimization resolves the contradiction by achieving both high heat resistance (Curie temperature ≥100°C) and high thermal shock resistance through the synergistic effect of these compositional adjustments
Solution Approach 2:
The patent creates a composite ferrite material system combining multiple metal oxides (CuO, NiO, ZnO, Fe2O3) with trace elements (B, Nb). This composite approach allows the material to simultaneously exhibit high heat resistance and thermal shock resistance by leveraging the complementary properties of each component, particularly the role of Cu and Ni in enhancing thermal stability while B and Nb improve structural integrity under thermal stress
2Strength
If ferrite material with insufficient heat resistance is used, then manufacturing is simpler, but the flexural strength after thermal shock deteriorates
Solution Approach 1:
The patent specifies precise compositional parameters: CuO (2-8 mol%), NiO (12-19 mol%), ZnO (28.5-33 mol%), Fe2O3 (48.2-49.7 mol%), B (5-25 ppm), and Nb (6-25 ppm). These controlled parameter changes achieve high flexural strength after thermal shock (≥100 N) while maintaining manufacturability through a systematic formulation approach that balances performance requirements with production feasibility
3Reliability
If conventional ferrite composition is used, then production cost is lower, but magnetic permeability and Curie temperature are insufficient
Solution Approach 1:
The patent optimizes the compositional parameters to achieve magnetic permeability ≥850 and Curie temperature ≥100°C by precisely controlling the ratios of CuO (2-8 mol%), NiO (12-19 mol%), ZnO (28.5-33 mol%), and Fe2O3 (48.2-49.7 mol%). The addition of trace B (5-25 ppm) and Nb (6-25 ppm) further enhances magnetic properties while maintaining cost-effectiveness through minimal quantities of these expensive elements
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The ferrite sintered body achieves high flexural strength after thermal shock, high magnetic permeability, and a high Curie temperature, making it suitable for high-temperature applications such as automotive uses.
Implementation Method 1
the drum core is produced by forming and sintering a ferrite material
Data Source
AI summary
A ferrite sintered body contains from 48.2% by mole to 49.7% by mole Fe in terms of Fe2O3, from 2.0% by mole to 8.0% by mole Cu in terms of CuO, from 12.0% by mole to 19.0% by mole Ni in terms of NiO, and from 28.5% by mole to 33.0% by mole Zn in terms of ZnO, in which when Fe, Cu, Ni, and Zn are converted to Fe2O3, CuO, NiO, and ZnO, respectively, and when the total amount of the Fe2O3, the CuO, the NiO, and the ZnO is 100 parts by weight, the ferrite sintered body contains from 5 ppm to 25 ppm B in terms of elemental B and 6 ppm to 25 ppm Nb in terms of elemental Nb.