Optimization of Soft Magnetic Alloys: A Comparative Analysis of 1J46, 1J50, 1J79, and 1J85 Grades
Abstract
Soft magnetic alloys play a critical role in various electrical and electronic applications due to their excellent magnetic properties. This article evaluates and optimizes four key grades—1J46, 1J50, 1J79, and 1J85—based on their chemical composition and mechanical properties as per the GBN198-1988 standard. The analysis focuses on resistivity, saturation magnetostriction, hardness, and tensile strength to guide material selection for high-performance applications.
1. Introduction
Soft magnetic alloys are widely used in transformers, inductors, and electromagnetic shielding due to their high permeability and low coercivity. The 1J series (1J46, 1J50, 1J79, and 1J85) offers varying compositions of nickel (Ni), molybdenum (Mo), and iron (Fe), making them suitable for different operational requirements. This study compares their properties and suggests optimization strategies for enhanced performance.
2. Chemical Composition and Key Characteristics
2.1 Nickel-Iron Alloys (1J46 & 1J50)
1J46 (45-46.5% Ni): Exhibits moderate magnetic properties with balanced Mn (0.6-1.1%) and Si (0.15-0.3%).
1J50 (49-50% Ni): Higher Ni content improves magnetic permeability while maintaining low carbon (≤0.03%).
2.2 High-Nickel Alloys with Molybdenum (1J79 & 1J85)
1J79 (78.5-81.5% Ni, 3.8-4.1% Mo): Low magnetostriction (2×10⁻⁶) and high resistivity (0.55 μΩ·m) minimize eddy current losses.
1J85 (79-81% Ni, 4.8-5.2% Mo): Ultra-low magnetostriction (0.5×10⁻⁶) ideal for precision sensors and high-frequency applications.
3. Mechanical and Magnetic Properties
Grade | Resistivity (μΩ·m) | Saturation Magnetostriction (×10⁻⁶) | Tensile Strength (MPa) | Elongation (%) |
1J46 | 0.45 | 25 | 735 (Annealed) | 3 |
1J50 | 0.45 | 25 | 685 (Annealed) | 37 |
1J79 | 0.55 | 2 | 560 (Annealed) | 50 |
1J85 | 0.56 | 0.5 | - | - |
Key Observations:
1J79 & 1J85 exhibit superior resistivity and minimal magnetostriction, making them suitable for high-frequency applications.
1J50 offers better ductility (37% elongation) compared to 1J46 (3%), beneficial for forming processes.
4. Optimization Strategies
Annealing Treatment: Improves ductility in 1J50 (37% elongation) and reduces hardness in 1J79 (120 HBs).
Alloy Refinement: Increasing Mo content (as in 1J85) enhances resistivity and reduces core losses.
Impurity Control: Strict limits on C, P, and S (≤0.03%, ≤0.02%) ensure consistent magnetic performance.
5. Applications
1J46/1J50: Transformers, relays (moderate magnetic fields).
1J79/1J85: High-frequency inductors, magnetic shielding (ultra-low magnetostriction).
6. Conclusion
The 1J series alloys provide a versatile range of soft magnetic materials. For high-frequency applications, 1J85 is optimal due to its ultra-low magnetostriction, while 1J50 offers better mechanical workability. Future work should explore nano-crystalline modifications for further performance enhancement.