Supermalloy

The core advantage of Supermalloy lies in the precise composition control of its nickel-iron-molybdenum system. By incorporating approximately 79% nickel and 5% molybdenum, the alloy simultaneously brings its magneto-crystalline anisotropy constant (K₁) and magnetostriction coefficient (λ) close to zero. Combined with a high-temperature hydrogen annealing process (treatment in pure hydrogen atmosphere at 1300°C), its initial permeability (μᵢ) can reach 50,000–150,000, and its maximum permeability (μₘₐₓ) can be as high as 600,000–1,200,000, making it the soft magnetic material with the highest permeability currently available, far exceeding ordinary permalloys (μᵢ of approximately 10,000–30,000). This property enables it to achieve extremely high flux response even under very weak magnetic fields.

Thanks to its high purity and optimized crystalline texture, Supermalloy exhibits extremely low coercivity (Hc ≤ 1.2 A/m), resulting in a minimal hysteresis loop area and significantly lower hysteresis losses compared to ordinary permalloys. In alternating magnetic fields, it demonstrates excellent core loss performance, making it particularly suitable for applications with stringent requirements on signal fidelity and efficiency such as pulse transformers, magnetic amplifiers, and weak-signal current transformers. Compared to ordinary permalloys, Supermalloy can operate stably under conditions where frequency and pulse duration are three times higher.

The resistivity of Supermalloy is approximately 0.60 μΩ·m (60 μΩ·cm), significantly higher than that of ordinary permalloys (about 45–55 μΩ·cm). The addition of molybdenum effectively increases the alloy's resistivity, reduces eddy current losses, and enables superior core efficiency in medium- and high-frequency applications. This characteristic makes it suitable for scenarios with strict requirements on efficiency and temperature rise, such as high-frequency transformers, radar systems, and aviation power supplies (400Hz).

Supermalloy exhibits excellent hot and cold workability, enabling it to be rolled into extremely thin strips (with thicknesses below 0.05 mm), as well as strips, bars, and wires in various forms. Its ductility surpasses that of most brittle soft ferrite magnetic materials, making it suitable for manufacturing complex laminated cores, magnetic shields, and precision stamped parts. Final annealing optimizes magnetic properties by eliminating processing stresses, restoring permeability, and reducing coercivity. Conventional machining (turning, milling, drilling, grinding) can be employed, but final finishing is recommended to use grinding or electrical discharge machining (EDM).