What are the surface treatment skills of NdFeB magnets:

NdFeB magnet degreasing: Alkaline degreasing agents, emulsifiers, and organic degreasing are very corrosive to NdFeB, and they are easy to rust after degreasing and washing, forming a yellow rust film;

NdFeB magnet pickling: NdFeB is easy to oxidize, and neodymium is easy to absorb moisture. Shortening the processing steps can reduce the consumption of NdFeB, and the link that has greater corrosion to NdFeB occurs during the pickling process, which is relatively dilute nitric acid + slow Etching agents are widely used, and the pickling time is short. Because dilute nitric acid is oxidizing, it is easy to cause the neodymium iron to be oxidized. The dilute nitric acid solution quickly changes from colorless to yellow, and the main component is composed of neodymium and iron compounds; If the washing time is too long, the surface will accumulate dust and it is not easy to clean. After pickling, the surface is in an activated state and is more likely to rust;

NdFeB magnet passivation: The production process of NdFeB is different from that of stainless steel, which is formed by smelting. The first is powder bonding and sintering. The intergranular structure of neodymium, iron and boron is not dense, and it contains adhesives. Microporous materials, strong oxidizing acid passivation solution will only increase corrosion; alkaline passivation solution is used for iron-based products (including stainless steel passivation, the effect is relatively general), general alkaline passivation solution is used for neodymium iron Boron still has a temporary anti-rust effect. After closing treatment, the effect may be better. Alkaline passivation treatment can not be less than one step such as degreasing, washing, pickling, washing, passivation, and water washing. , Even cleaning with alcohol, the working hours and cost are relatively large; phosphating is used for the surface treatment of NdFeB, which can only provide a temporary anti-rust effect, and the process is complicated;

 NdFeB magnet sealing treatment: NdFeB sealing is mainly used for electroplating or electroless plating pretreatment, air bubbles after painting also need to be sealed;

 Four-in-one treatment for neodymium-iron-boron magnets: Based on the analysis of neodymium, iron and process, the development of degreasing, rust removal, passivation and rust prevention, sealing four in one, normal temperature (temperature 30-40 degrees is better), using ultrasonic Combined with NdFeB four-in-one treatment liquid for cleaning treatment, the time is usually about 10 minutes. Regarding the appearance of less oil and only floating rust (not rust spots) NdFeB products are suitable for four-in-one treatment, and the effect is better than phosphorus It is very suitable for post-treatment process (post-treatment: electroplating, electroless plating, electrostatic spraying, epoxy resin)