Phosphating is a mature metal surface conversion coating technology that forms an insoluble phosphate protective film on the metal substrate through chemical reactions. This film is typically gray in color, water-insoluble, and primarily composed of iron, zinc, or manganese phosphates. The film thickness is generally controlled within the range of 5 to 20 micrometers.

      Ningbo Yuanchen New Materials Co., Ltd. has applied the phosphating process to the surface protection system of high-performance NdFeB permanent magnets, launching a series of phosphated NdFeB products. While maintaining the original magnetic properties of the magnets, this product provides antioxidant and anti-corrosion protection through the phosphate film, effectively mitigating the oxidation susceptibility of NdFeB magnets. Featuring cost-effectiveness, process maturity, and excellent adhesion to the substrate, phosphating treatment is suitable for short-term protection of NdFeB magnets and as a pre-treatment prior to coating.

Core Features

Good Corrosion and Oxidation Resistance

      The phosphating solution exhibits good wettability and adhesion to the porous surface of the magnets. The treated magnets possess a certain level of salt spray resistance and chemical medium resistance. Phosphating helps reduce the risk of oxidation during storage and logistics. The treated magnets feature uniform color and a smooth surface. When combined with vacuum packaging, the shelf life can be extended, providing reliable interim protection for subsequent processing.

Excellent Adhesion and Coating Compatibility

      The phosphate film bonds firmly to the base metal, and its microscopically dense and porous structure provides an effective anchoring effect for subsequent organic coatings. When used as a primer, it significantly enhances the bond strength between the outer coating and the magnet, thereby improving the durability of the overall protection system.

High Electrical Insulation

      The phosphate film possesses high volume resistivity and can serve as a functional electrical insulation layer. The treatment process is mild, ensuring that the mechanical properties and magnetic parameters of the magnetic material remain virtually unchanged, meeting the dual requirements for insulation and magnetic performance in components such as motors.

Cost-Effective and Flexible Process

      The phosphating process is streamlined with stable raw material supply and low comprehensive treatment costs, making it suitable for mass production. Additionally, the phosphate film can be removed via standard acid pickling processes, facilitating rework or seamless integration with subsequent procedures, thus offering strong production adaptability.

Dimensional Precision and Magnetic Property Retention

      As an in-situ conversion coating process, phosphating involves minimal substrate dissolution during film growth, resulting in negligible dimensional changes that do not affect the tolerances of precision parts. The controllable processing temperature prevents demagnetization or degradation of mechanical properties.

Technical Capabilities and Qualifications

      Founded in 2003, Ningbo Yuanchen New Materials Co., Ltd. is a National High-Tech Enterprise that has established a complete industrial chain integrating R&D, manufacturing, machining, surface treatment, magnetizing, packaging, and logistics of magnetic materials. The company’s independently developed high-performance NdFeB magnetic materials achieve a remanence (Br) of up to 15 kGs and an intrinsic coercivity (Hcj) of up to 35 kOe (specific performance subject to technical agreements).

      The company operates an annual production capacity of 1,500 tons of NdFeB magnets, supported by over ten surface treatment processes including zinc plating, tin plating, nickel plating, zinc-nickel alloy plating, copper-tin alloy plating, phosphating, and electrophoresis. The phosphating process covers multiple systems such as zinc-based, iron-based, and manganese-based formulations, supporting various process routes including high-temperature, medium-temperature, and ambient temperature (15°C to 35°C), allowing flexible matching according to customer operating conditions. The company has obtained management system certifications including IATF 16949, ISO 9001, ISO 14001, ISO 45001, and QC 080000, ensuring standardized and controllable production processes.

Application Areas

      Short-Term Storage & Transit Protection: Used for magnets awaiting final surface treatment decisions during production, providing basic antioxidant protection to minimize performance degradation during warehousing.

      Pre-Treatment Before Coating: Serves as a primer for epoxy resin, electrophoretic paint, and other coatings to enhance the adhesion and corrosion resistance of composite protection systems.

      Inverter Air Conditioner Compressors: Single-phosphated magnets are suitable for potting and encapsulation processes, meeting the insulation and rust-prevention requirements of air conditioner compressors.

      Motor Silicon Steel Sheet Insulation: Utilizing the insulating properties of the phosphate film to replace traditional insulating paper or oxide films for inter-lamination insulation in motor cores.

      Lubricant Carrier for Metal Cold Working: The porous structure of the phosphate film absorbs lubricants, providing friction reduction and wear resistance during cold forming processes such as drawing and stamping.

Customization Services

      Yuanchen New Materials supports customization of phosphate coating types, including zinc-based, iron-based, and manganese-based formulations. Parameters such as coating weight, process temperature, and post-treatment solutions can be adjusted based on application scenarios. Leveraging integrated capabilities from material R&D to finished product testing, we provide customers with full-process technical support and customized solutions ranging from magnet selection and structural design to surface treatment.

Compliance Notice and Disclaimer

      Technical indicators mentioned herein, including film thickness ranges, magnetic performance parameters, and process temperatures, are derived under standard testing conditions. Actual performance may vary due to differences in substrate condition, process parameters, and operating environments. Specific acceptance criteria shall be subject to the technical agreement signed by both parties.

      Phosphating provides temporary protection; for long-term outdoor use or harsh corrosive environments, it is recommended to combine this treatment with additional surface protection processes.

      No restricted substances such as lead, cadmium, mercury, or hexavalent chromium are intentionally added during the design and production of this product, which is managed in reference to relevant environmental regulations including RoHS and REACH. Given the dynamic nature of regulatory updates and the complexity of supply chain traceability, specific compliance status should be verified against third-party test reports and applicable customer standards.

      Yuanchen New Materials consistently adheres to the principles of technological innovation and quality priority, dedicated to providing customers with reliable, compliant, and cost-effective magnetic material solutions.