A Breakthrough in Internal Coating
InnerArmor technology is “Hollow Cathode Plasma Immersion Ion Processing” (HCPIIP). It is the first process capable of applying high-performance coatings—extremely hard, smooth, corrosion-, erosion- and wear-resistant coatings—on the internal surfaces of parts.
The patented InnerArmor process offers major technological advantages over traditional coating technologies:
- Higher plasma density— Hollow Cathode Plasma Immersion Ion Processing (HCPIIP) creates an order of magnitude higher plasma density than traditional Chemical Vapor Deposition (CVD) techniques. Key benefits include fast coating rates for cost effectiveness, conformal coating across internal and external surfaces and strong corrosion protection with dense pinhole-free coatings.
- Elimination of traditional chamber-based processing— This enables a broad range of part support. The InnerArmor process is applied directly to one or multiple parts, which can range in size up to 40 feet long. Thus, the process works equally well on small components, such as bearings or valves, and large components, such as tubing joints and pump rotors.
- Customizable coating characteristics— InnerArmor coatings can be adjusted to meet the needs of the application. By varying the gases involved in the process, the coatings can be customized to deliver the properties necessary for the application. InnerArmor coatings may be created out of virtually any gas that can be ionized. The technology is capable of depositing carbon-based coatings, metal carbides and oxides. Example coatings include silicon carbide and diamond-like carbon (DLC) films.
The InnerArmor coating is deposited in a three-step process to ensure maximum adhesion to the base substrate:
- Plasma Clean– initial phase completes the preparation process and removes any remaining surface impurities.
- Plasma Adhesion– second phase delivers an adhesion layer which ensures a strong chemical bond to the substrate.
- Plasma Coating– final phases deliver a layered coating, which is customized to meet the application requirements.
Many industries make extensive use of pipes, couplers, tanks, valves, cylinders, etc. through which fluids, gases or materials flow. Prior to Sub-One, various techniques attempted to protect, strengthen or enhance the internal-surface performance of such parts, but each method had fundamental limitations…
For example, parts were sometimes manufactured from special high-grade metals and then machined for extra smoothness, but this was an expensive proposition. Traditional coating methods—electroplating, sprays and others—provided limited effectiveness because they were primarily intended for external rather than internal surfaces. Plus, they were often toxic or environmentally dangerous. InnerArmor technology eliminates all those problems and produces a hard, smooth, corrosion- and erosion-resistant internal surface on a variety of base materials—while substantially reducing costs.
InnerArmor advantages over thermal spray coating
Thermal sprays such as arc, plasma and High Velocity Oxy-Fuel (HVOF) spray deposit melted materials onto a surface. However, these are line-of-sight processes that cannot reach into small, complex or very long cavities, such as pipes. And spray-coated surfaces are rough, increasing friction or requiring additional grinding and polishing. Often done by hand, spray coating is expensive and difficult to apply evenly. In contrast, InnerArmor coating is fully automated, less expensive, smooth and evenly applied, even in very long cavities.
InnerArmor advantages over chrome plating
Chrome plating uses harsh, hazardous chemicals that pose health risks and face more stringent government regulations. Also, for aggressive environments, chrome often requires special additional pre-coatings. And imperfect or inadequate surface preparation can cause multiple chrome plating problems, such as microcracking, delamination and substrate corrosion. In comparison, InnerArmor provides superior hardness, wear and corrosion resistance, and it utilizes an environmentally benign process.
InnerArmor advantages over polymer linings
These linings are plastics such as PTFE coatings that are sprayed or dip-coated onto the product. These coatings provide limited corrosion resistance, are not optimal for high-wear components and cannot be used in high temperature environments. InnerArmor coatings prevents corrosion, resists wear and performs at much higher temperatures.
InnerArmor coatings offer important advantages over virtually all traditional treating and coating techniques as well as over newer processes such as CVD diamond.
InnerArmor: high-performance inner coatings
Top: Cross section of 304 stainless steel pipe—uncoated.
Middle: Same steel pipe with InnerArmor silicon oxy-carbide coating.
Bottom: Same steel pipe with InnerArmor DLC diamond-like carbon.
