Why are resin-bonded diamond cutting discs best suited for cutting Iron-based amorphous?

Amorphous iron—also known as metallic glass—is a novel type of soft magnetic material that emerged in the 1970s. Produced via a rapid quenching process, its physical state is characterized by a disordered, amorphous arrangement of metal atoms; this structure differs fundamentally from the crystalline lattice of silicon steel, making it significantly more amenable to magnetization and demagnetization.
Material Characteristics: Low loss at high frequencies, high saturation magnetic induction, and exceptional thermal stability.
Application Fields: Its usage is rapidly expanding from traditional power distribution transformers into emerging sectors such as new energy, high-end equipment manufacturing, and electric transportation.

Challenges in Cutting Iron-based Amorphous

Hard and Brittle Nature: Cutting operations frequently result in edge chipping, cracking, or the formation of micro-cracks.
Stress Sensitivity: Mechanical cutting induces internal stresses that directly degrade the material’s soft magnetic properties and increase iron loss.
Ultra-Thin and Prone to Deformation: When cutting thin ribbons (typically 20–30 μm thick), the material is highly susceptible to wrinkling, lateral deviation, and warping.
Heat Sensitivity and Crystallization Risk: Heat generated during cutting—or thermal effects from laser processing—can cause the amorphous structure to crystallize, rendering the material unusable.
High Precision Requirements: Cutting dies are prone to rapid wear; maintaining precise blade clearance is difficult, often leading to burrs and material delamination.
Process Limitations: Laser cutting and other thermal cutting methods are generally unsuitable; only precision cold cutting techniques can be employed, leaving an extremely narrow margin for processing error.

For cutting amorphous iron, resin-bonded diamond cutting wheels are the universally recognized first choice, while resin-bonded CBN cutting wheels are not suitable.

Selection Instructions for Cutting Consumables of Amorphous Iron

Cutting Amorphous Iron: Resin-bonded Diamond Cutting Wheels Are Preferred; Resin-bonded CBN Cutting Wheels Are Not Suitable

Amorphous iron has high hardness, high brittleness, and poor fracture toughness, so it belongs to hard and brittle materials. CBN cutting wheels are designed for machining high-hardness ferrous metals with certain toughness, such as hardened steel, die steel, and bearing steel. The material properties are completely mismatched.

Resin CBN Cutting Disc

Why CBN Is Not Suitable for Cutting Amorphous Iron

• Mismatched Application Objects
  CBN is known for processing hard and tough steels. Amorphous iron is hard but brittle and easy to crack under pressure, which does not match CBN’s application conditions.
• Inappropriate Cutting Method
  CBN abrasive grains are tough and relatively blunt, mainly cutting by extrusion and pressing, which easily causes chipping and micro-cracks. Diamond grains are sharper with shearing cutting, ideal for low-stress cutting of hard brittle materials.
• Industry Standard Selection Principle
  Follow the rule: Diamond for hard brittle materials; CBN for hard tough steels. Diamond wheels are used for ceramics, cemented carbide, and magnetic materials. CBN wheels are only for tool steels, stainless steel, and high-temperature alloys, not for brittle special metals.
• Chemical & Process Compatibility
  Amorphous iron is mainly iron. Diamond may react with iron at high temperatures, but resin-bonded diamond wheels with wet cutting can control temperature strictly and avoid crystallization. Although CBN is chemically stable with iron, its mechanical properties and cutting mechanism do not match amorphous iron.

 Diamond Cutting Wheels: Why Resin Bond Is Used Instead of Metal Bond

Amorphous iron is extremely sensitive to temperature, vibration, and mechanical stress. The core differences between resin bond and metal bond are as follows:

Temperature Control & Anti-crystallization (Core Key)

Amorphous iron crystallizes above 300–500°C and loses soft magnetic properties.

• Resin-bonded diamond cutting disc: Low thermal conductivity, blocks friction heat, and realizes low-temperature cutting with wet cutting to prevent crystallization.
• Metal-bonded diamond cutting disc: High thermal conductivity, transfers heat quickly, easily causes overheating, crystallization, discoloration, and cracks.

 Self-sharpening Performance

• Resin bond: Automatically releases dull grains, keeps sharp, low heat and low stress.
• Metal bond: Holds grains tightly even when dull, causes rubbing, squeezing, burrs, and micro-cracks.

Vibration Damping & Anti-cracking

• Resin bond: Elastic and shock-absorbing, reduces edge chipping and micro-cracks.
• Metal bond: High rigidity, easy to produce rigid impact and brittle cracks.

Resin Diamond Cutting Disc                                             Metal Diamond Cutting Disc

Summary & Recommendations

• Amorphous iron (hard and brittle material) must use resin-bonded diamond cutting wheels. CBN wheels are strictly prohibited.
• Only resin-bonded diamond wheels are allowed; metal-bonded diamond wheels are not suitable.
• Wet cutting must be used to ensure low-temperature, low-stress cutting and protect the structure and magnetic properties of amorphous iron.