Grain oversize: Grain oversize is one of the common problems in the use of iron electroplated zinc-nickel alloy. The grain size is too large which leads to the reduction of the strength of the material and makes it easy to rupture and deform.
Author: Anna
The common faults in the process of electroplating zinc-nickel alloy and their causes are as follows:
Grain oversize: Grain oversize is one of the common problems in the use of iron electroplated zinc-nickel alloy. The grain size is too large which leads to the reduction of the strength of the material and makes it easy to rupture and deform. Grain size can be controlled by controlling parameters such as temperature and current density of the plating solution, in addition, some additives can be added to change the grain size.
Incomplete crystallization: Incomplete crystallization will lead to uneven and rough surface of iron electroplated zinc-nickel alloy, which will affect its beauty and service life. The surface quality of the material can be improved by optimizing the crystallization process, including adjusting parameters such as the composition and temperature of the plating solution, as well as adjusting parameters such as current density and electrode distance.
Air bubbles on the surface: Air bubbles may appear on the surface of iron-plated zinc-nickel alloys, and these bubbles can reduce the corrosion resistance of the material, thus affecting its service life. Bubbles can be controlled by controlling parameters such as air pressure and stirring speed of the plating solution, in addition, some special additives can be used to improve the surface quality of the material.
Pinholes and pockmarks: Pinholes and pockmarks are caused by poor pre-plating treatment and improper heat treatment process. Pinholes are fine holes formed due to air bubbles trapped on the surface of plated parts, which will affect the protective performance and aesthetics of the plated layer. The generation of pinholes and pockmarks can be reduced by optimizing the pre-treatment process, controlling the current density and solution composition.
Plating peeling: Poor adhesion between the plated layer and the substrate or brittleness of the plated layer is the main cause of plating peeling. It can be improved by improving the pre-plating treatment process, adjusting the ratio of brightening agent, controlling the current density, etc. to improve the adhesion between the plated layer and the substrate and reduce the occurrence of hydrogen embrittlement.
Poor corrosion resistance: thin nickel plating layer has poor corrosion resistance due to high porosity. Double nickel and multi-layer nickel system can be used to improve the corrosion resistance of the plating layer
Hanging green corrosion: When using VCF I 385 antirust cutting fluid to seal the plated layer after plating, the undesirable phenomenon of hanging green may be formed. This can be avoided by optimizing the sealing treatment process.
Copper exposed in the bore: Because the deep plating ability of bright nickel plating solution is not as good as that of cyanide plating dark copper, the bright nickel plating layer after plating can not completely cover the copper plating layer in the inner hole part of the product, which leads to the undesirable phenomenon of copper exposed in the bore. This problem can be solved by improving the plating process or using a more suitable hole treatment method.