NdFeB zinc series phosphating solution and application method thereof

Abstract

The invention discloses an NdFeB zinc series phosphating solution. The NdFeB zinc series phosphating solution is composed of Zn2+, PO43-, NO3-, F-, an accelerant and Ni2+, wherein the amount-of-substance concentration ratio of Zn2+ to PO43- to NO3- to F- to the accelerant is (54-74) :(163-183) :(126-146) :(50-70) :(3-5), the concentration of the accelerant ranges from 0.1 g / L to 1.3 g / L, and the concentration of Ni2+ ranges from 0.01 g / L to 0.2 g / L. The phosphating solution and water are prepared into a work solution according to the ratio of 1:10. According to work parameters, the free acidity ranges from 5% to 8%, the total acidity ranges from 30% to 40%, the phosphating temperature ranges from 50 DEG C to 55 DEG C, the phosphating time ranges from 10 minutes to 15 minutes, NdFeB is treated to generate a light grey or grey phosphating film, the soaking time of 3% neutral saline water is three hours or above, the cross-cut test of a paint film obtained after cathode electrophoresis is the degree 0, and the time of the neutral salt spray test of the paint film obtained after cathode electrophoresis is 550 hours or above. The phosphating solution is high in film-forming thickness and fine in film layer crystallization on treated workpieces, the surface is smooth and dense, the corrosion resistance is excellent, the solution is stable, less sediment is generated, and the time of the salt spray test is longer; and meanwhile no organic complexing agent is included in the formula, the enterprise cost is reduced, and the environment is protected.

Description

technical field [0001] The invention relates to the field of metal surface treatment, in particular to a neodymium-iron-boron-zinc phosphating solution and a use method thereof. Background technique [0002] At present, the anti-corrosion technology of NdFeB surface includes electroplating, organic coating and composite coating. [0003] Due to the relatively low equipment cost of the electroplating process. The shortcomings of the electroplating coating are also quite obvious: the consistency and stability of the product quality are generally poor, the coating has a large porosity, the film is not dense, and has shape dependence. plating. For some severe occasions, after long-term use of the coating, problems such as cracking, peeling, and easy falling off will occur, and the protective performance will decrease. [0004] The use of electrostatic spraying or electrophoretic deposition coating process can obtain relatively high film quality, which is more suitable for bat...

AI Technical Summary

Problems solved by technology

The NdFeB treated with this phosphating solution has a relatively thick phosphating film, which is not suitable for cathodic electrophoretic coating, and the alkali resistance of the phosphating film is poor due to the high zinc content in the phosphating solution