We all know that the most commonly used NdFeB plating process can be divided into two kinds of plating and hanging plating, this article focuses on the introduction of the next plating process.
Base specific process is as follows: Bake degreasing a closed a light a wash a barrel (with steel ball) an ultrasonic degreasing a water wash a water wash an acid wash a wash a wash a wash a wash a wash water activated an ultrasonic Wash a roll plating ~ wash a wash a dry water.
There are several processes in this process flow that are not found in conventional barrel plating, which is a process designed for the material characteristics of NdFeB products. Special attention should be paid to these processes.
(1) baking degreasing
NdFeB products are similar to porous sintered powder metallurgy products, in the process will inevitably have oil and other dirt into the hole and not easy to remove. The easiest way is to use the strong oxidizing effect of the air temperature to make the oil in the hole evaporate or askew so as to eliminate the hidden danger of poor bonding in the future.
Encapsulation is one of the commonly used surface treatment methods for porous materials. The common method is to use a method of sealing powder metallurgy, that is, a method of immersing zinc stearate, heating the zinc stearate in a metal container to melt (130 - 140 ℃), then the products after baking degreasing immersed in molten zinc stearate, soak about 25min. Remove and place in the oven at 600 ℃ for about 30min, or at room temperature for more than 2h to cure.
(3) rolling light
After the closure of the workpiece but also for the rolling treatment, so that the surface oxide, burr, sealant and so on after rolling are removed and present a new metal crystal surface. Depending on the surface condition of the abrasive used, it is usually hardwood sawdust material, but also artificial abrasive (artificial pumice, etc.). The ratio of workpiece to abrasive is 1: (1 ~ 2). In order to improve the rolling effect, you can add a little 0P emulsifier, the amount of water to submerge the workpiece is appropriate, drum hexagonal as well, speed 30 ~ 40r / min, the time is 30 ~ 60min.
(4) to the membrane
To the film is due to the surface of the NdFeB products after acid etching residue on the surface layer of black film, if not removed, will affect the coating adhesion. These black film should not be removed with ordinary strong acid, organic acid can be added in 150mL / L concentrated hydrochloric acid 15g / L, at room temperature for about 2min.
Article from NdFeB Industry Network