Electrolytic and chemical plating Surface Treatments

This information can be found at information under the name "Process overview".

No he doesn’t has to mention it, but has to know that it is a necessary part of the plating process and that it can be of influence on the design.

Yes, it will be addressed on sheet 49.

Is no part of this presentation. Not enough time for that. We should do this in a more detailed and extensive presentation. As agreed we focused only on the Aalberts Surface Treatment Coatings in Eindhoven.

The chemical coatings and conversion coatings do and general the heat treatment coatings too. Lacquer coatings and polymer coatings not.

Roughness has to be defined before and after coating. We can determine then depending on the thickness and the type of process if it is possible to reach the roughness after plating.

The coefficient of friction stays the same as long as the coating lasts. Depends on the used material. Better when aluminum is used, less when hardened steel is used.

You have to specify this but there are ISO standards for each process, normally they are used for this purpose.

How lower the temperature of the process the easier it is to mask. The most imported thing is however the shape and the locations of the area’s which has to be masked.

I will explain during discussing the design rules.

I will explain during discussing the design rules.

Yes, but not when anodizing.

Not discussing this in an early phase with a plating company.

Nickel-strike is an electrolytic activation process which is used for getting good adhesive chemical and electrochemical coatings on stainless steel and other nickel and chrome containing alloys. Without this process you can’t get adhesion on these metals.

The process is done by applying a very thin nickel coating under a reducing environment on the stainless steel and other alloys parts.

Re-plating is a process in which a coating is removed of a part and after that the coating is again plated on the part.

This is done for instance when : - The coating is rejected due to a plating failure - The part has to be machined partly due to dimension change and thus the coating has to be replaced - The wrong coating is on the part. - Repair of the part, etc. - Etcetera, etcetera

Yes, is already in the possession of KSC, but can also be requested from Aalberts Surface Treatment Eindhoven.

You are right.

When you want to visual determine which coating is on a part you need some experience and it all depends on the type of coating. Coatings like Tin, Silver and nickel are easy recognizable but the difference between chemical nickel and electrolytic nickel is also for us almost not visible.

The same counts for the difference between gold and gold/cobalt and a lot of other alloy coatings. So in general, determining coatings by visual examination is not possible. You have to use XRF or X-Ray for that.

Silver plated layers are in principle good resistant against oxidizing and chemical attack. Sulfur however will attack silver and will lead to the forming of silver sulfides on the surface of the plated parts.

This silver sulfide changes the white appearance of the silver into a yellow or even black color. The sulfides which create this silver sulfide layer are already present in the atmosphere. SO2 , H2S and CS2 are gases which are very normal in an industrial atmosphere so this will always occur.

The silver sulfide layer is a very thin layer. The thickness of this layer varies from about 30 nanometer until 150 nanometer and is very soft. It doesn’t influences the good properties of the plated silver metal but it will slightly effects the contact resistance.

Due to the fact that the silver sulfide layer is a soft it is easily penetrated and destroyed by pressure so current flow will always be assured. Fully prevention of the forming off this silver sulfide layer is, except with transparent lacquer, varnish or transparent metallic layers, not possible.

Protective layers just like passivation solutions for silver postpone this process for a while but will never completely prevent it.