1J50

1J50 (UNS K94840) is a high-permeability iron-nickel soft magnetic alloy containing approximately 50% nickel, optimized for excellent magnetic properties—specifically high initial permeability, maximum permeability, and low coercive force. Unlike corrosion-resistant alloys like Monel, this alloy is designed for magnetic applications, maintaining stable magnetic performance across a temperature range from -55 °C to 150 °C (218°F to 302°F). It is widely used in industries requiring precise magnetic control, such as electronics, telecommunications, and instrumentation, where low magnetic loss and high magnetic responsiveness are critical.

Behaviour that matters in service

• Excellent Soft Magnetic Properties — With 49 – 50.5% nickel content, it exhibits high initial and maximum permeability, combined with ultra-low coercive force—ensuring efficient magnetic flux conduction and minimal magnetic hysteresis loss, ideal for high-precision magnetic cores.
• Stable Magnetic Performance — Maintains consistent magnetic properties over a wide temperature range (-55 °C to 150 °C) and under low to moderate mechanical stress, avoiding magnetic degradation in harsh operating environments.
• Good Machinability — Can be easily processed via cold rolling (for thin strips), cutting, and drilling with standard tooling; annealing (at 800 – 900 °C in hydrogen atmosphere) post-machining further optimizes magnetic properties by reducing internal stress.
• Low Magnetic Loss — Minimal hysteresis loss and eddy current loss at low to medium frequencies (up to 10 kHz), making it suitable for transformers, inductors, and other AC magnetic components requiring energy efficiency.

Typical applications

• Electronics & Telecommunications — Used in small transformers, inductors, and magnetic cores for signal processing equipment (e.g., telecom filters, sensor coils), where high magnetic permeability ensures clear signal transmission.
• Instrumentation — Applied in magnetic shielding cases for precision instruments (e.g., oscilloscopes, analytical balances), magnetic yokes for galvanometers, and core components for current transformers—reducing external magnetic interference.
• Automotive Electronics — Utilized in automotive sensors (e.g., ABS speed sensors, position sensors), ignition coils, and voltage regulators, where stable magnetic performance withstands engine vibration and temperature fluctuations.
• Medical Equipment — Suitable for magnetic resonance imaging (MRI) accessories (e.g., gradient coils), medical sensors, and diagnostic device components—complying with biocompatibility standards and ensuring low magnetic noise.
• Renewable Energy — Used in small-scale power transformers, inductor cores for solar inverters, and energy storage system (ESS) magnetic components, where low magnetic loss improves energy conversion efficiency.
• Aerospace & Defense — Employed in avionic sensors, radar magnetic cores, and navigation system components (e.g., compass magnetic shields), where high reliability and temperature stability meet aerospace-grade performance requirements.