At ADV Plating, we find that electroless nickel plating is a popular method of coating instruments and components with long-lasting and uniform layers. This treatment does not require an electrical current and involves the use of either a nickel-boron or nickel-phosphorus alloy applied to a substrate to improve both wear resistance of certain components while reducing friction. One popular variant is that of electroless nickel plating with PTFE, or polytetrafluoroethylene. It has many advantages, but it also has its own limitations that our customers must consider when thinking about its use in their business. Let’s look at some of the limitations of electroless nickel plating with PTFE (specification SAE AMS 2454).
- Expensive. When compared with other coating options, electroless nickel plating with PTFE may be more expensive. This is primarily due to the higher cost of the required chemicals and the increased labor costs associated with the more challenging application.
- Limited thickness. Electroless nickel plating options can effectively produce highly uniform coatings. The maximum thickness of the nickel coating is .003” (75 microns). Any thicker runs the risk of pitting. However the average thickness of most EN PTFE applications is only .0003” to .0005”.
- Environmental concerns. PTFE is an unregulated chemical that belongs to the fluorinated polymer subgroup of the PFAS family of chemicals. PFAS have come under increased scrutiny in recent years due to their negative impact on the environment. When choosing to use PTFE, consideration should be given to no not only its use, but the entire lifecycle of the PTFE from production to disposal.
- Adhesion issues. EN PTFE can be applied to many different types of metal. The most common metal substrates are steel or aluminum, although we also see requests for brass and stainless steel. However, the more resistant a metal is to oxidation the more challenging it is to achieve strong adhesion.
- Limited material compatibility. Non-metals and some metals (i.e. titanium) are not appropriate for electroless nickel plating, as some may react adversely with the chemicals utilized during the plating process. This effectively limits the types of substrates that can be treated in this manner.
- Surface finish appearance. Unlike a regular nickel finish, EN with PTFE appears light blue in color. Sometimes a white powder residue is visible which is excess PTFE particles. This residue can be removed with additional processing steps such as light bead blasting.
- Wear resistance limitations. Components which need to achieve extreme wear resistance might not be suitable for electroless nickel plating with PTFE as it can result in reduced hardness compared to alternative coating methods.
- Hydrogen embrittlement. Another possible issue with the process of electroless nickel plating on steel is the potential for hydrogen embrittlement. During the plating process, the buildup of excess hydrogen atoms may lead to stress cracks and brittleness in the coating. To minimize this risk, parts can be baked after plating to relieve the stress.
Who can I contact to discuss the benefits of electroless nickel plating with PTFE?
At ADV Plating, we are here to help with coating components, parts, and pieces of both industrial and commercial products to ensure longevity and improved lifespan of devices and machines used in your business. If you are curious about electroless nickel plating with PTFE, we welcome you to contact us to learn more about what we can do for your business.
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