Soft Magnetic Alloy Vacuum Brazing

1. Material Properties

Magnetic alloys refer to alloys with ferromagnetic properties, which are divided into two categories: soft magnetic alloys and hard magnetic alloys. Soft magnetic alloys have high magnetic induction and permeability, and small coercive force and hysteresis loss. They have good rust resistance and processability, and can be made into components with extremely precise shapes and sizes. , In the aviation industry and the electronics industry, it is used to make electronic components with high sensitivity, precise size, small size, low high frequency loss, good time and temperature stability, and special functions.

2. Brazing Characteristics

Brazing of soft magnetic alloys in vacuum can purify materials, eliminate internal stress and improve magnetic properties. However, the chemical composition of these alloys is strictly controlled, and the addition of solder should not damage the performance of the soft magnetic alloy itself. In addition, the cooling rate after brazing has a great influence on the magnetic properties and should be strictly controlled. Vibration and knocking during brazing assembly will affect the magnetic properties. The heat treatment temperature of these alloys is high (1000~1200C), and the brazing temperature can be compatible with the heat treatment temperature. If a fixture is selected for positioning, the thermal expansion coefficient of the fixture material should be close to that of the soft magnetic material.

3. Solder Selection

Various brazing filler metals that can wet iron and nickel-based alloys can be used for brazing of soft magnetic material parts. Silver-based solder and copper-based solder are preferred for parts working below 400C; for components between 400 and 800C, manganese-based, titanium-based and nickel-based solders are usually used, and gold-based or palladium-based precious metals can also be used for special needs Brazing filler metals; cobalt-based or nickel-based filler metals such as Ni-Cr-Mo, Ni-Cr-Si-W, etc. can also be used for work between 800C and 1000C.