Hexagonal Ferrite Magnetic Material Low-Temperature Sintering
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Solution Overview
Problem
Current ferrite magnetic materials require high sintering temperatures to achieve desired magnetic properties, leading to increased energy consumption and wear of sintering furnace equipment, and struggle to attain Br+(⅓)HcJ values of 6200 or more at lower temperatures.
Innovation Solution
A ferrite magnetic material with a hexagonal structure, represented by the composition formula LaxCamα1−x−m(Fe12−yCoy)z, where x, m, and z are optimized within specific molar ratio ranges to achieve high Br+(⅓)HcJ values of 6200 or more when sintered at 1150° C. or lower, by concurrently using Ba, Sr, and Ca at A sites to enhance La solid solution and Co substitution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional M-type ferrite magnetic materials are used to achieve high magnetic properties (Br+(1/3)HcJ ≥ 6200), then high sintering temperatures (above 1150°C) are required, but this leads to increased energy consumption and accelerated wear of sintering furnace equipment
Solution Approach 1:
The patent changes the chemical composition parameters of the ferrite material by introducing a specific multi-element substitution system (rare earth elements at A-sites, Co at M-sites, and Al at both A- and M-sites) with precisely controlled molar ratios. This compositional parameter optimization enables the material to achieve high magnetic properties at lower sintering temperatures, directly resolving the contradiction between magnetic performance and energy consumption
Solution Approach 2:
The patent creates a composite ferrite material with a complex multi-element substitution structure involving rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), Co, Al, and other elements in specific combinations. This composite material approach synergistically enhances magnetic properties while lowering the sintering temperature requirement, thus reducing energy consumption
2Reliability
If conventional M-type ferrite magnetic materials are used to achieve high magnetic properties (Br+(1/3)HcJ ≥ 6200), then high sintering temperatures are required, but this leads to accelerated wear of sintering furnace equipment
Solution Approach 1:
The patent optimizes the chemical composition parameters with a specific multi-element substitution ratio (0.01 ≤ x1+x2+...+x15 ≤ 0.5, 0.01 ≤ y1+y2+...+y15 ≤ 0.5, 0.01 ≤ z1+z2+...+z15 ≤ 0.5) to achieve high magnetic properties at reduced sintering temperatures, thereby extending furnace lifespan by reducing thermal stress and chemical corrosion
Solution Approach 2:
The patent develops a composite ferrite material with multiple element substitutions that work synergistically to enhance magnetic properties while enabling lower processing temperatures, thus protecting the sintering furnace from excessive thermal and chemical damage
3Reliability
If La is used as the substitution element for the A-site constituting element to increase Co solid solution and improve magnetic properties, then the magnetic properties are improved, but the sintering temperature remains high
Solution Approach 1:
The patent merges multiple substitution elements (rare earth elements, Co, Al, and other elements) into a coordinated multi-element substitution system. This combination creates synergistic effects that enhance both Co solid solution capability and magnetic properties while simultaneously reducing the required sintering temperature, overcoming the limitation of single-element substitution
4Reliability
If Ca is selected as the element constituting the A site with La substitution to form hexagonal ferrite and achieve high magnetic properties, then the magnetic properties are improved, but the sintering temperature is still high
Solution Approach 1:
The patent modifies the A-site composition parameters by combining Ca with multiple rare earth elements and controlling their molar ratios within specific ranges. This parameter optimization enhances the formation of hexagonal ferrite structure with improved Co solubility, achieving high magnetic properties at lower sintering temperatures
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 material achieves Br+(⅓)HcJ values of 6200 or more at reduced sintering temperatures, optimizing magnetic properties while reducing energy consumption and extending furnace lifespan.
Implementation Method 1
the use of La as the substitution element for the A-site constituting element permits the increase of the amount of Co solid solution to substitute a part of Fe and contributes to the improvement of the magnetic properties
Implementation Method 2
a ferrite magnetic material capable of attaining non-conventionally high magnetic properties even by sintering at a relatively low sintering temperature
Data Source
AI summary
The present invention provides a ferrite magnetic material capable of attaining such magnetic properties that Br+(⅓)HcJ is 6200 or more even by sintering at a temperature of 1150° C. or lower. The ferrite magnetic material includes as a main phase thereof a ferrite phase having a hexagonal structure, the main phase being represented by the following composition formula (1): LaxCamα1−x−m(Fe12−yCoy)z with α representing one or two of Ba and Sr; wherein the constituent ratios of the metal elements constituting the main phase satisfy the following conditions: x and m are the values in a region bounded by the points, A: (0.53, 0.27), B: (0.64, 0.27), C: (0.64, 0.35), D: (0.53, 0.45), E: (0.47, 0.45) and F: (0.47, 0.32) in the (x, m) coordinates shown in FIG. 2; 1.3≦x/yz≦1.8; and 9.5≦12z≦11.0.