Nanovate CoP - Corrosion and wear protection for steel
Corrosion and Wear Protection for Steel
Steel used in aggressive environments with corrosion coupled with high wear have traditionally used electroplated "engineered" hard chrome (EHC) for surface protection. While other electroplated metals provide good corrosion resistance (like cadmium (Cd) and Zinc Nickel (ZnNi)), they are removed quickly under wear conditions, leaving the steel exposed to corrosion. In recent years, there has been a push to replace toxic hard chrome plating to improve worker health and safety.
Nanovate CoP Plating
Integran has developed an electroplated nanocrystalline Cobalt, called Nanovate CoP (also referred to as nCoP), that is a cost effective and higher performance, drop-in replacement for hard chrome plating. The process has been proven stable through industrial application of millions of amp hours, and there are industrial products with the material in the field since 2008. The process is covered by the US DoD Mil-Spec "MIL-DTL-32502 - COATING, COBALT-PHOSPHORUS ALLOY, NANOCRYSTALLINE -(ELECTRODEPOSITED)". An SAE - AMS Specification for the process is in the approval process (Document B13AA - "Nanocrystalline Cobalt-Phosphorus Electroplating") as of November 2013.
Integran licenses the technology to interested parties (currently deployed to Navair, Pratt and Whitney, and Enduro Industries), and offers low volume production and application engineering through it's facilities in Toronto. The material is particularly well suited for sliding wear applications (hydraulics, pneumatics) and high chloride corrosion environments (salt spray, muriatic acid wash-downs etc.).
The material/process has the following benefits:
1) Lower Labor Cost
The Nanovate CoP has a high deposition efficiency (over 90% vs 15-25% for hard chrome) allowing parts to be processed at incredible speed. With plating rates of up to 200 microns/hour (imagine 30 microns in 8 minutes!), your labor rate for plating your parts will go down dramatically. Given this is usually ~50% of plating a part, the savings can be significant.
2) Lower Plant/Electrical Costs
The high deposition speed also opens the door to replacing multiple chrome lines with a single Nanovate CoP line. This reduces the plant cost per processed unit and means less tanks, power supplies and electrochemistry for the same through-put.
If your plant is processing parts at peak capacity with the plating process being the bottleneck, plating using the Nanovate CoP process offers a way to increase your capacity.
On the maintenance, repair and overhaul (MRO) side, repairs requiring thick build-up can be processed much quicker, resulting in less downtime for customers and a shorter backlog for suppliers.
In addition, instead of wasting 80% of your electricity generating gas and heat during deposition, you now use almost all your power in depositing metal, reducing electricity costs per part processed.
3) Higher Corrosion Resistance
The corrosion resistance of Nanovate CoP far exceeds that of hard chrome because the material is not microcracked. There is no need for expensive Nickel underlayers that are common with hard chrome usage in high corrosion environments.
The corrosion performance also opens the door to reducing thickness, which further reduces the cost of the part.
4) Lower Friction/Sliding Wear
The lower coefficient of friction of Nanovate CoP over hard chrome and contributes to better sliding wear performance, and therefore lower seal leakage rates.
5) Improved Fatigue Performance
In aerospace, many parts are designed based on steel strength and fatigue performance is critical in maintaining a minimum strength over repeated loading of the parts (aircraft landing gear is a great example). As the Nanovate CoP plating is a high strength structural cladding, it minimizes the fatigue debit imparted on the steel. In lower strength steels, it can actually impart a fatigue credit! This is in stark contrast to hard chrome which imparts a very significant fatigue debit, which results in heavier over-designed parts.
6) High Spalling Resistance
The high elastic limit (~1%) of nanocrystalline Nanovate CoP makes for high spalling resistance in high strain applications. This stands it apart from other processes like thermal sprayed (HVOF) ceramic materials which have a very low strain capability and have a tendency to spall under repeated high strain applications. See our blog post comparing Nanovate CoP to HVOF for more details.
The process is covered by the US DoD Mil-Spec "MIL-DTL-32502 - COATING, COBALT-PHOSPHORUS ALLOY, NANOCRYSTALLINE -(ELECTRODEPOSITED)". An SAE - AMS Specification for the process is in the approval process (Document B13AA - "Nanocrystalline Cobalt-Phosphorus Electroplating") as of November 2013.
Want to know more?
Blog - Nanovate CoP to HVOF comparison blog post