Basic Knowledge of Amorphous and Nanocrystalline Industry

The full name of amorphous materials is amorphous soft magnetic materials, also known as amorphous alloys.

The full name of nanocrystalline materials is nanocrystalline soft magnetic materials, also called ultra-fine crystallite.

Ultra-fine crystallite is the early designation of nanocrystalline materials, for its grain size ranges from 10 to 20 nanometers.

The atomic structure of amorphous materials features long-range disorder and short-range order.

The atomic structure of nanocrystalline materials presents both long-range and short-range order.

1K101 is the national standard grade for amorphous materials, mainly composed of iron, silicon and boron.

1K107 is the national standard grade for nanocrystalline materials, mainly composed of iron, silicon, boron, copper and niobium.

The mainstream amorphous materials are Fe-Si-B (iron-based), Ni-based (nickel-based), with a small amount of Co-based (cobalt-based) products.

The mainstream nanocrystalline materials are Fe-Si-B-Cu-Nb (iron-based), Ni-based (nickel-based), with a small amount of Co-based (cobalt-based) products.

Large amorphous refers to 1K101, while small amorphous refers to 1K107.

1K107A/B/C/J and other models are developed based on the 1K107 composition system.

Minor composition adjustments are made to achieve different targeted performance indicators.

 

 

Advanced Knowledge

Saturation Magnetic Induction (Bs) refers to the maximum magnetic flux that a material can sustain.

Unit: Tesla (T)

Amorphous: Saturation magnetic induction at about 1.56 T

Nanocrystalline: Saturation magnetic induction at about 1.25 T

 

Coercivity (Hc) represents the anti-demagnetization capability of materials.

Unit: Ampere per meter (A/m)

Amorphous: Coercivity at about 3.0 A/m

Nanocrystalline: Coercivity at about 1.2 A/m

 

Initial Permeability (μi) indicates the magnetic sensitivity under weak magnetic fields.

The test adopts small signal excitation at 1kHz and 1V approximately.

An LCR meter or impedance analyzer is used to measure inductance variation, and the initial permeability (μi) is calculated combined with magnetic circuit parameters.

Amorphous: Initial permeability at about 5,000

Nanocrystalline: Initial permeability at about 80,000

 

Resistivity (ρ) means the electrical resistance of conductive materials.

Unit: Ohm-meter (Ω·m)

Amorphous: Resistivity 140 Ω·m

Nanocrystalline: Resistivity 90 Ω·m

 

Crystallization Temperature is the critical temperature at which the internal structure of a material begins to transform into a crystalline state.

Unit: Degree Celsius (℃)

Amorphous: Crystallization temperature around 450℃ → Annealing temperature limited to 380～410℃

Nanocrystalline: Crystallization temperature around 500℃ → Optimal annealing temperature: 540～570℃

 

Curie Temperature (Tc) is the critical temperature at which magnetic materials completely lose magnetism.

Unit: Degree Celsius (℃)

Amorphous: Curie temperature around 410℃

Nanocrystalline: Curie temperature around 570℃

 

Density reflects the compactness degree of materials.

Unit: Gram per cubic centimeter (g/cm³)

Amorphous: Density approx. 7.25 g/cm³

Nanocrystalline: Density approx. 7.2 g/cm³

 

Stacking Factor = Volume of effective magnetic materials inside the core ÷ Overall external volume of the magnetic core

Amorphous: Stacking factor: 0.85～0.89

Nanocrystalline: Stacking factor: 0.75～0.82