Day in, day out, marine and naval equipment is subject to extreme conditions including, salt water, high temperatures, wear, corrosion and fatigue. The problem which comes with these conditions, is the length of downtime needed to repair key marine components and equipment.
Every second a vessel spends in the shipyard is one where it’s not delivering value. In the USA alone, investment in shipbuilding has grown steadily, with gross output in 2013 topping $28 billion. With these figures, it’s crucial to minimize downtime.
Despite the presence of other on-board repairs, such as machining, welding and plumbing, one of the biggest challenges when a ship or submarine is at sea, is putting metal back onto a part which has been over machined, worn, or corroded. With no time for sending vital components out for repair, selective brush plating has – for many years – been the method of choice.
This well-established and reliable process has already been written into shipbuilding specifications including the American Bureau of Shipping, Mil-STD 2197(SH) and NAVSEA. It’s a portable method of electroplating localized areas of metal surfaces for OEM components, permanent repairs and salvaging worn or mis-machined parts; providing a fast, efficient and targeted solution to corrosion, wear, galling, solderability and brazing. But the main benefit is portability. It can be brought into the shipyard, aboard vessels for on-board repairs, or anywhere it’s needed to enhance or repair components.
The SIFCO Process® has been adopted by naval forces across the US, UK and Japan, and is used on a wide range of components across the fleet. On turbine casings, for example, AeroNikl® has been successfully used for interference fits, providing a metal-to-metal seal with less risk for thermal disturbance than the previous repair method, welding.
Elsewhere, copper capped with AeroNikl® is used to fill pitting on seal surfaces of components such as main sea water valves and water tight hatches for missile tubes on aircraft carriers and submarines. In these cases, selective plating can prevent the need either for disassembly and transportation to a machine shop (sea water valves), or for in-place machining after tig welding (water tight hatches).
The SIFCO Process® saves engineers and technicians thousands of dollars every year by cutting downtime, turnaround time and investment in new equipment. To learn more visitwww.sifcoasc.com/marine
NASF has released a study pointing to the finishing industry’s major success in reducing metals discharges to local water treatment utilities in recent decades. The surface finishing industry is subject to two categorical standards for wastewater discharged to publicly owned treatment works (POTWs). In the past three years, the U.S. Environmental Protection Agency (EPA) has conducted a review of the categorical standards and discharge limits. During that time, the NASF has been working closely with EPA officials to provide information and analysis on the industry’s progress on wastewater discharge improvements.
Metals Loading Study
As part of an effort to develop useful data, NASF recently commissioned a metals loading study of wastewater discharged to the Milwaukee POTW. This study repeated a similar study conducted in 1992. The primary results of the study are summarized below:
The number of surface finishing facilities decreased from 104 in 1993 to 51 in 2016
The total metals discharged to the POTW were reduced by 87.6% since 1992
The average metals per facility discharged to the POTW were reduced by 72.0%
The surface finishing industry discharged only 2.1% of the metals discharged to the POTW in 2016
The number of facilities in Significant Non-Compliance decreased from 50% in 1989 to approximately 8% in 2016 (only 4 facilities)
Factors Driving Improved Environmental Performance
The study identified four general trends and reasons for the increase in environmental performance:
Facilities learned to operate their waste water treatment systems better over time
The better performing facilities survived the several economic downturns over the period between the studies
Facilities have better operational controls to maximize treatment efficiency
Facilities implemented pollution prevention practices that reduced the metals discharged
Based on the industry’s discussions with facilities and the wastewater utility community, these significant reductions are representative of surface finishing nationwide as the technology and science for managing wastewater treatment is fundamentally the same throughout the industry. This study clearly demonstrates that the surface finishing industry has made significant progress in reducing the metals in its effluent, providing evidence that revisions to the existing categorical standards for the industry are not needed at this time.
NASF has presented this information to EPA, and the agency is expected to make a final decision this summer on whether it will pursue revisions to the existing metal finishing and electroplating categorical standards and discharge limits.
For additional information about this study or EPA’s review of the existing waste water discharge standards, please contact Christian Richter or Jeff Hannapel with NASF at crichter@thepolicygroup.com or jhannapel@thepolicygroup.com.
SIFCO ASC Environmental Support Services
The SIFCO Process® of Selective Electroplating provides superior electroplated deposits and anodized coatings with minimal waste. Utilization of the SIFCO Process® enables companies to meet or exceed most industrial requirements while remaining sensitive to environmental regulations.
There is no question that environmental regulatory enforcement is significantly different today than years ago. The terminology alone can be baffling until studied and understood. SIFCO ASC has a thorough knowledge of the regulations which are mainly promulgated by OSHA and the EPA. Our Environmental Services Department is charged with staying current with environmental regulations and assisting our staff and customers. These environmental support services are available to all SIFCO Process® customers by calling SIFCO Applied Surface Concepts headquarters at 216-524-0099.
Small internal diameters can be tricky to repair when they’re mis-machined. The benefit of selective plating is being able to isolate the bore with minimal masking to complete the plating operation. When one of the most advanced engineering facilities in Scotland experienced this situation, they called on SIFCO ASC to build their bores back to the size they require. The Challenge
The engineering company manufacture large THRT Adaptors. Each component contains ten 0.750” diameter bores. When one of the bores was mis-machined to 0.755” a repair was needed. An out of tolerance bore could cause a variety of problems for the overall performance of the component. If for a bearing fit, the bearing would be too loose and spin. If the bore was meant for a pressure or interference fit, over machining would cause the fit to be loose not allowing the component to perform correctly.
Multiple repair options were investigated for resizing before choosing selective plating. Due to the size of the part in comparison to the size of the area needing repaired, tank plating was immediately disregarded. The part is too large, and the bore is far too small – requiring significant masking to make tank plating a viable option. While welding or thermal spray could achieve a successful result, the risk of thermal distortion involved in both processes was too great. In addition, both processes are unable to reach far enough into the bore to provide the correct thickness required. Solution
This left selective plating as not just the only option, but the best application for the re-sizing repair. While selectively plating small internal diameters is a difficult job, the company fortunately approached the experts at SIFCO ASC.
The engineers at SIFCO ASC designed a special flow anode to ensure that proper thickness and uniformity was achieved. Because the required deposit for the application was AeroNikl 250®, the anode was made from a Nickel 200/201 alloy as so to not break down the tool or contaminate the solution during the plating process. The tool was also designed to be long enough to extend out of the bore and away from the face of the part. The flow holes then extended down the length of the entire tool allowing for solution to flow into the back of the bore. The Result
The customer wanted 0.008” – 0.010” of AeroNikl 250® built up within each bore to give them enough material to machine back to size. Prior to the application, the parts were masked to protect to rest of the component. The initial pre-plate procedures were: Electroclean, Activator No. 2, Activator No. 3, and Nickel Special for bonding. AeroNikl® was then deposited to about 0.015” thick.
The final result of the application was extremely successful. With the specially designed tooling, SIFCO ASC was able to build up the deposit over the requirement of the customer, providing a good quantity of deposit material to machine back to the drawing tolerance of 0.750”. Without the technology of selective plating, a valuable machined component may have had to have been completely remanufactured – saving them time and expense, while meeting the challenges of salvaging critical components.
For more information on other applications in the oil & gas industry, visit our website. To download a pdf of this case study, click here.
There are hundreds of plating specifications in today’s industries. Military and independent specifications can be hard to understand and even harder to determine which approved vendor to use.
Military specifications are continually revised to help restore military equipment and preserve capital investments of the military systems. Through preventive maintenance and service checks, military equipment is maintained in accordance with its design specifications. To ensure repairs are conducted in the same manner every time, specifications or standard have been developed.
Independent standards are also routinely revised by SAE and IAQG to assure customer satisfaction. Aviation, space and defense organizations implement initiatives that make significant improvements in quality and reduction in cost throughout all levels of the supply chain.
The most applicable standards to SIFCO ASC, and electroplating, are as follows:
Military
Mil-Std-2197 (SH) – This is a Navy standard for brush plating. This document is intended to provide guidance to military activities in developing a contact plating capability, and to aid in choosing applications for the process which can save time and money without sacrificing the reliability of the part plated or system in which it is used.
Mil-Std-865 – This is an Air Force standard for selective brush plating. Currently this document is being restructured to primarily direct operators to follow the recommendations of the solution manufacturer.
QQ-N-290 – This is a tank plating standard for nickel. All SIFCO ASC nickels meet the performance provisions of this standard.
QQ-P-416 – This is a tank plating standard for cadmium. All SIFCO ASC cadmiums meet the performance provisions, Type I, and Type II of this standard.
Mil-A-8625 – This is a tank anodizing for Type I chromic, Type 1C boric-sulfuric, Type II sulfuric and Type III hard coat. All SIFCO ASC anodizing solutions meet the performance requirements of this standard.
Independent
AMS 2451 – SAE wrote the AMS 2451 standard for the general requirements of brush plating. As Mil-Std 865 is now inactive for new designs, AMS 2451C – revised in 2011 – serves as its replacement. Within the specification some of the most used and accepted tank standards are listed and referenced.
AMS 2403 – This is a tank plating standard for nickel. All SIFCO ASC nickels, except 2085, 5644, 5646, and 5650, meet the performance provisions of this standard
AMS 2423 – This is a tank plating standard for nickel. SIFCO ASC’s AeroNikl® 400 & 575 meet the performance provisions of this standard.
AMS 2424 – This is a tank plating standard for nickel. SIFCO ASC’s AeroNikl® 250 meets all performance provisions.
If you have a need for plating to any of the specifications listed, contact us at 800-765-4131 or info@sifcoasc.com. For a list of all of the industry specifications we meet, click here. For a list of all commercial specification met, click here.
There are several metal add-on processes that a shop can use to repair a worn or damaged component, but for this article we’ll review only the most common: welding, spray, and electroplating (tank and brush). Welding
If asked to name one metal add-on repair process, most would immediately be able to identify welding. Welding is one of the oldest, and most well-known metal add-on repair processes. During the process, multiple beads of weld are applied next to and on top of each other until sufficient thicknesses are built up. Adhesion is very good, but depending on the application, deposit purity and oxide inclusions can be an issue. Welded surfaces will always require a final machining or grinding operation to achieve tight tolerances. Welding can also create stress in the base metal and may cause heat distortion. While this is typically not a problem on large components, distortion can be an issue on small cross-sectional areas.
Electroplating: Tank
Tank, or bath, electroplating is also well-known metal surface finishing process. While tank plating has many advantages, such as plating in batches and the ability to plate irregularly shaped parts, it also has serious disadvantages. All the parts to be repaired must be disassembled before plating (and ultimately reassembled upon completion). Also, if only a small area of the component needs plated, time-consuming masking is required. Many components in the marine, aerospace, and oil and gas industries are too large for standard tank sizes or are extremely difficult to mask – to ensure protection of adjacent areas. Finally, the system requires continuous chemical solution control and large, expensive equipment. While widely used, tank plating does not lend itself to the typical maintenance shop, therefore parts are typically sent out, rather than repaired in-house.
Electroplating: Brush
Brush plating, or selective plating, is a method of electroplating on a localized area without the use of an immersion tank. The SIFCO Process® equipment is portable, enabling technicians to plate parts in place with minimal disassembly, minimizing downtime. In a typical operation, the part is first masked to isolate the area to be plated and then a series of base material-specific preparatory steps are conducted to ensure an adherent deposit. The last step is the plating of the metal deposit to the desired thickness. Most brush plating applications are dependent upon the operator; but when properly executed, brush plating can provide precise build-ups, minimizing post machining or grinding. With the brush plating method, there is also no risk for thermal distortion, internal stresses or cracking from heat. Of all the metal-add processes, brush plating is the most precise, while providing the best adhesion.
Spray
Spray metallizing includes thermal spray applications such as flame spray, plasma spray, HVOF, and others. With all thermal spray applications metal rod, wire, or powder are melted and sprayed onto the component’s surface using a special gun. Using this technique, as much as one-eighth inch (3mm) of metal, intermetallic alloys, or metallic oxides or carbides can be deposited quickly and inexpensively. However, subsequent machining is typically needed when tight tolerances are involved. While the porous deposits may be advantageous for oil bearings, they are not suitable for many applications, especially when corrosion protection is a requirement. But, the biggest drawback of using thermal spray is its adhesion. Of the four metal add-ons, thermal spray has the poorest adhesion.
Overall, each type of metal add-on repair has its advantages and disadvantages, but if you are looking for an application to repair your component in place, and to size, you needn’t look further than brush plating.
For more information about SIFCO’s brush plating services, please contact us at 800-765-4131 or info@sifcoasc.com
Reducing ergonomic risks. Increasing usable capacity. Whatever your reason, if you’re looking to learn more about how to automate your plating operation, you can’t miss this presentation at SURFIN 2018.
The advancements in automated selective plating incorporate options for total customization to the customer’s specific application. To illustrate this, data, video and pictures of a vertical, dual- spindled automated ID plating machine will be presented. By working with the customer, custom plating machines can be developed to reduce operator set-up time, part handling, and even number of applications – effectively achieving betting lead times and meeting production schedules.
Join us at 8:30am on Wednesday, June 6 at the NASF SUR/FIN 2018 Expo where Derek Kilgore will demonstrate how attendees can achieve consistent quality and process repeatability by incorporating automated selective plating into their process.
Derek is the Mechanical Design and Project Engineer for SIFCO Applied Surface Concepts in Independence, OH. He is a graduate of the University of Akron, in Akron, Ohio with a Bachelor of Science in Mechanical Engineering and has 10 years of experience in the field. Derek has worked on projects in the surface finishing, food packaging and automotive industries such as: automated selective plating systems, metal stamping, blow molding, injection molding, thermoforming, rubber manufacturing, and more.
When two stainless steel parts are in direct contact with one another, the constant friction can result in galling of the metal. Just ask Cutting & Wear Limited (C&W). C&W are an international supplier of downhole tool technology to equipment manufacturers worldwide. C&W contacted SIFCO Applied Surface Concepts because they needed to selectively plate a thin layer of copper for anti-galling purposes onto the threads of newly manufactured stainless-steel components while meeting their customer specifications.
C&W manufacture Flow Exit Cylinders for the oil & gas industry. The cylinders are made out of UNS S17400 H900. UNS S17400 H900 is a chromium-copper precipitation hardening stainless steel that is used for applications requiring high strength and corrosion resistance. Due to the base metal material, the threaded connection of the cylinder is threatened by galling, corrosion, and leakage. Adding to the difficulty, often the ends of the cylinders are treated with a delicate “Zintec” coating, which can be easily damaged.
C&W had investigated multiple options to provide the lubricity and anti-galling properties they required. Unfortunately, both options posed too big of a risk to the part and to the existing Zintec coating. Barrel plating – a process in which components are placed in an electrolyte solution in a barrel, then rotated or tumbled to provide an even coat – was discarded because the fragility of the components. While tank planting was rejected because the cylinder components would need to be heavily masked to protect Zintec coated ends. Also, tank plating was not financially viable due to the small quantity needing plating.
The answer came in the form of selective plating. The SIFCO Process® of selective plating, is a portable electroplating method used to enhance, repair, and refurbish localized areas on manufactured components without the use of an immersion tank. As only a small deposit of copper was needed to provide the lubricity and anti-galling required, and with the volume of components being low, selective plating was chosen as the ideal procedure. By using isolated masking techniques and a power pack, technicians were able to plate within drawing tolerances without the need for post machining.
Prior to the application of copper, the parts were carefully masked to protect the Zintec coating. Selective plating requires movement of the anode, the part, or both. For this application, the cylinders were placed in a turning head, or lathe, while the operator held the anode stationary, ensuring good flow to the anode for quality deposits on the deep threads. The initial pre-plate procedures were: Electroclean, Activator No. 4, Activator No. 1, and Nickel Special for bonding. Copper was then deposited onto the deep threads, allowing for the right amount of lubricity and anti-galling on the mating parts.
By using selective plating C&W was able to plate a limited quantity of components in less than half the time it would have taken for tank plating, and at less cost. And SIFCO ASC now plates these cylinders on a regular basis. According to James Kilner, Production Data Controller at C&W, “We use SIFCO ASC because their work is always of high quality, they always turn our parts around in good time, and they have excellent customer services. We wouldn’t use anyone else for our copper coating.”
For more information on our anti-galling coatings, or plating of threads and grooves, visit www.sifcoasc.com/oil-gas
High strength and low weight, coupled with the ability to readily form a tenacious surface oxide film, make titanium and its alloys useful in many applications in the aerospace, industrial and medical fields.
A limitation of titanium alloys is the relatively poor resistance to adhesive wear, which results in galling and cold welding, poor fretting behavior and a high coefficient of friction. One can overcome this limitation by providing a surface coating. Coatings are also applied for heat reflection, emissivity, corrosion resistance in hot acidic environments, conductivity, lubricity, brazing and resizing.
Surface Preparation
Titanium is very reactive and rapidly forms an oxide film whenever the metal surface is exposed to air or any environment containing available oxygen. This oxide layer should be removed before electroplating or other surface treatment, but its tenacity makes removal problematic.
Surface roughening can improve coating adhesion, and can be accomplished by abrasion, grit blasting and etching. Surface preparation is key to achieving robust adhesion of any coating to titanium, as nickel brush plated over the oxide film results in poor adhesion in localized areas.
SIFCO Applied Surface Concepts has performed multiple experiments on titanium for surface preparation and selective plating. Our R&D department obtained titanium sheets 1.1 mm thick and tubes 0.83 mm thick in three substrate materials: Ti-6Al-4V, Ti-6Al-6V-2Sn and commercially pure Grade 2 titanium, and mechanically finished the surfaces using several techniques including dry or wet abrasion, wire brushing and abrasive blasting.
Mechanical Methods
R&D used mechanical methods to improve adhesion by increasing the substrate surface area and exposing a fresh, clean titanium surface. Mechanical working of the surface by abrasion with grinding media, wire brushes or by blasting with silicon carbide, or wet or dry alumina increased surface area and improved deposit adhesion. But, adhesion was still not high enough to routinely survive a 180° bend test.
Acid Etch
They then undertook to identify an electrochemical treatment method with the capability to increase the substrate surface area in a controlled manner and provide an oxide-free surface that enabled good deposit adhesion. The resulting electrochemical treatment includes both an electrolyte and an anodic/cathodic etch/activate methodology to promote microetching of the titanium surface to increase surface area and reduce the surface oxide. This electrochemical treatment resulted in excellent adhesion. The plating procedure given in Table 1 was used to make a quality deposit.
Several factors contribute to the excellent adhesion: mechanical interlocking, increased surface area and lack of an oxide film. These three attributes were generated during the brush plating process. Brush plating is particularly suited for generating these attributes because of the small volume of electrolyte, close contact between the anode and the cathode, and the rapidity with which electrolytes can be switched from activation to strike plating.
Important considerations for the procedure are:
Keep the titanium under potential control at all times
Keep the plated area 100% covered by the wrapped anode
Use rapid switching from anodic to cathodic
Allow no rinsing between steps
Do not reuse the solution.
Other Evaluations
The surface of titanium alloy stubs were pretreated by machining or SiC grit-blasting, then abrading, etching and activating using the process in Table 1. A 50-μm thick nickel deposit was plated from two acid electrolytes. The failure mode in all specimens was adhesive, at the nickel coating – titanium interface.
Hydrogen embrittlement was tested according to General Motors Engineering Standard GM3661P, and all samples were satisfactory for hydrogen embrittlement — that is, no failure or cracking was observed on the any of the coupons.
This technology also performed well with Ti-6Al-6V-2Sn alloy, and deposit adhesion was satisfactory. However, the procedure does not provide a deposit with adequate adhesion on Grade 2 titanium. Deposits on Grade 2 generally passed tape tests but failed bend tests.
Future research work will continue to develop principles for good adhesion of plated deposits to titanium alloys, and identify a process to deposit coatings with improved adhesion on Grade 2 titanium. Deposition of other materials with better wear resistance than titanium will also be investigated.
What is selective plating? How does the SIFCO Process® work? What type of deposits can I plate? What are the benefits of selective plating? Get all of your questions answered and more, by watching our new video.
Die tooling specialist, Lasercomb Dies produce steel counter plates, which are lined with grooves that are used to form creases in carton packaging. However, when the alignment for one of the creases was in the wrong position, it resulted in aesthetic damage to the stainless-steel die print piece. Initially, Lasercomb was unsure as to whether the component was still fit for use and was considering replacing it, but after exploring the implications of producing an identical component, it became clear that carrying out a repair was a more viable option.
Fortunately, the damage was in a very small localized area, therefore a quick setup could be achieved with minimal masking. Given the nature of the issue, there were relatively few options available, these being selective plating and tank plating. The problem with the latter was it offered relatively little control of the deposit and since the damage was limited to a small area, it would need a vast amount of masking, hence, selective plating was the more practical option. This method offers control when applying the deposit by and was able to fill the damage dress back, apply the cap and blend into the finish.
The SIFCO Process® was so successful that the component was restored to perfect condition, resulting in savings in excess of £2,500 – what it would have cost to re-produce the component.
Perhaps even more significant is the minimal impact the repair had on productivity. Had Lasercomb been unable to salvage the component, they would have needed to produce another – which could have taken up to 30 hours, as well as incurring extra cost for materials and associated production costs.
Kevin Holmes, Quality Manager at Lasercomb, explained: “We are extremely grateful to SIFCO ASC for providing an effective solution to a potentially tricky issue. By taking the time to assess the options available to us, SIFCO ASC was able to identify the most appropriate way to rectify the problem, saving us considerable time and money. Above all, the quality of the repair was outstanding to the extent that it was impossible to tell that the component had ever been damaged. We were extremely satisfied with the service we received and would be happy to use them again moving forward.”
To learn more about the SIFCO Process of selective plating or to speak with our technical department contact 800-765-4131 or info@sifcoasc.com
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