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The below was a proposed technical program for an event and may not represent the final program, nor the contents of the Conference Proceedings for that event. If you are seeking a particular paper, contact the event's sponsor to make sure it is an actual part of their Conference Proceedings before ordering them.
The American Electroplaters and Surface Finishers Society, Inc.
1996 Aerospace/Airline Plating & Metal Finishing
Forum & Exhibit
April 30-May 2, 1996
(Sorry, the beginning of this document is missing)
William Nebiolo, REM Chemicals, Inc., Southington, CT
Assorted aerospace components such as blades, vanes and airfoils are manufactured as machine turnings, forgings or lost wax castings. Manufacturing generate items with irregular surface profiles. Surface readings typically show Ra values of 60-600 min. Minimizing airflow resistance across component surfaces ensures optimal fuel economy and engine performance, therefore, most surface requirements specify finishes < 30 min. Labor-intensive, repetitive, hand-belting steps with successively finer polishing belts are the most common finishing techniques. Vibratory finishing is a hands-free technique, but requires several steps, starting with abrasive media and ending with non-abrasive burnishing media. The hand labor saved in belting is therefore lost in the repetitive vibratory steps. The use of media generated copious quantities of sludge. Finishing times of 8-10 hr are typical. In a chemically accelerated vibratory finishing process, a non-abrasive burnishing media is coupled with an activation chemistry to rapidly produce a smooth surface. The chemistry reacts with the surface of the component, forming a soft film that is easily smoothed by the wiping action of the non-abrasive media. Film formation and wiping proceed three to five times faster than standard vibratory finishing. Because non-abrasive media are utilized, repetitive tumbling steps, labor and sludge are minimized. Surface finishes < 5 min. are possible in time cycles as short as 2 hr. This paper will examine the advantages of chemically accelerated vibratory finishing versus the traditional hand-polishing techniques standard vibratory finishing methods.
9 a.m.--Non-cyanide Alkaline Copper Plating
Stan Olander, Electrochemical Products Inc., New Berlin, WI
This paper will focus on a non-cyanide, alkaline copper process that is being used successfully by many companies in the industry. The process is practical, does not require any electrolysis using auxiliary tanks and anodes, and is, therefore, economical. It works on steel, brass, white metal, zinc diecast and aluminum. Operating details of the process and production experience at a large jobshop will be presented.
9:30 a.m.--Understanding & Implementing ISO 14000 Environmental Standards for Aircraft Applications
Dr. Paul Piplani, Member, U.S. TAG, ISO/ TC207 Committee, TTX Environmental Inc., Sturgeon Bay, WI
The ISO 14000 series developed by Technical Committee 207 is intended to provide companies with the elements of an effective environmental management system that can be integrated with other management requirements to achieve environmental and economic goals. This paper will outline the final versions of the ISO 14000 guidance document and ISO 14001 specification used for certification/registration purposes, and provide a roadmap for the implementation of standards prior to ISO 14001 certification.
10:30 a.m.--HVOF-sprayed Coatings for Navy Jet Engine Component Repair
Donald S. Parker, Naval Aviation Depot, Naval Air Station, Jacksonville, FL
Continuing improvements to the mechanical properties of HVOF sprayed coatings have resulted in principal engine manufacturers implementing new overhaul repairs for components utilizing this technology. New techniques in powder manufacturing, new powder materials and application techniques have made repairs possible for components that were either restricted to the limits of chrome or nickel plating, or that were scrapped because no repair was available. The General Electric TF34 and F404, and the Pratt and Whitney J52 aircraft engine components are being repaired with HVOF sprayed chrome carbide/nickel chrome, Tribaloy T-800/T-400 and Inconel 625/718. Typical repairs involve bearing bores on main shafts, dimensional restorations and clearance control applications. Parameter optimization is performed by evaluating a Taguchi matrix of variables such as gas ratios and spray distances to develop the best mechanical properties. Macro- and microhardness are evaluated in relation to tensile bond strength and microstructure. Optimized parameters are published in a repair document for use in the production shop during engine overhaul once all mechanical properties, grinding and finishing requirements are achieved. This paper will provide examples of three different coating qualifications accomplished at the Depot in Jacksonville.
2 p.m.--A Multimedia Computer-steps assisted Learning Tool for Plasma Spray
Chunqing Cheng & E.J. Onesto, Concurrent Technologies Corporation, Johnstown, PA
A multimedia computer assisted learning (MCAL) tool with an intelligent interface was developed to help track technology developments and to facilitate the education and training needs of plasma spray practitioners. The MCAL tool uses the full potential of a multimedia personal computer running Microsoft reg. and Windows TM and combines technical needs with entertainment arts. With a click of the mouse, users can view a process demonstration on the computer screen, hear how it sounds and listen to a process description. Such a presentation eases the learning process and helps users rapidly digest a broad range of information. Integrated within the tool is a comprehensive database with information on plasma spray processing technology developments in a variety of formats. The MCAL tool lends itself to the expanded needs of plasma spray engineers. It provides a means to launch specific applications on remote powerful mainframe computers and workstations, as well as more general applications on local machines. The engineer can perform numerical simulation, as well as link to e-mail packages and World Wide Web information browsers. This work was conducted by the National Center for Excellence in Metalworking Technology, operated by Concurrent Technologies Corporation under contract to the U.S. Navy as part of the U.S. Navy Manufacturing Technology Program.
2:30 p.m.--Production Testing of Aqueous Cleaning Systems
Richard Pirrotta & David Roberts, Concurrent Technologies Corporation, Johnstown, PA
The NDCEE is conducting a project for the U.S. Army Armament Research, Development and Engineering Center to identify, test and evaluate the most environmentally compliant, technically and economically feasible non-halogenated metal parts cleaning system for the widest range of DOD applications. Production testing was performed in the NCDEE's Environmental Technology Facility to demonstrate the viability of non-halogenated cleaning systems by collecting qualitative and quantitative cleanliness results and process information for material compatibility, economic and environmental analyses. Testing consisted of the following: Selection of metal parts representative of those currently cleaned at DOD facilities; operation of the high pressure spray and ultrasonic cleaning system for 30 trials at various combinations of pressure, chemical concentration, wash time and wash/temp settings; determination of cleanliness levels achieved; statistical analysis of cleanliness test results; evaluation of material compatibility data; and collection of process information for material and energy balances. Cleanliness testing included visual examinations, tape lifts, wipe tests, surface tension tests, non-volatile residue tests and particulate residue tests. Production parts were subjected to a three-week immersion test to generate data for the evaluation of material compatibility characteristics. To gather process data for material and energy balances, the programmable logic controllers were linked to a computerized data collection system throughout production trial testing. Results indicate that the levels of cleanliness achieved during non-halogenated production testing are equal to or better than the levels of cleanliness obtained using current halogenated cleaning processes. Using statistical analysis techniques, the optimal operating conditions were identified for both cleaning systems. The material compatibility test results for the parts and aqueous chemistry used in the production trial testing were satisfactory. Part-specific material compatibility concerns, however, must be individually addressed for each application of an aqueous cleaning chemistry. Projected annual material and utility usage was calculated from the production trial testing material and energy balances. This information will be used as the basis for the economic analyses and environmental assessments.
3:30 p.m.--Recycling Aqueous Cleaners & Parts Washer Rinse Waters
Dr. Phil Rolchigo, Membrex, Inc., Fairfield, NJ
Aqueous cleaners are not free of drawbacks and limitations. Unlike vapor degreasing methods that recycle the active solvents, aqueous cleaners are rarely recycled. The cleaning process is a batch operation, ending when the cleaning solution has been exhausted by accumulated oils and soils. The nature of this batch cleaning process results in both higher, cleaner replacement costs and the incremental costs of oily waste disposal. This disposal problem also applies to
'"'biodegradable'"' cleaners because discharge to the drain is prohibited once they are contaminated with waste oils. Ultrafiltration systems are ideal for recycling aqueous cleaners. A membrane separates the oils, dirt and other pollutants from the cleaner and water so that they can be recycled into the parts washer, keeping the parts washer tank fresh for continual cleaning. A typical parts tank life is extended four times when using an ultrafiltration system.
4:00 p.m.--Alkaline Cleaning of Hollow Turbine Airfoils
Gary Lomasney, Pratt & Whitney, East Hartford, CT
Mandated elimination of Class I Ozone-depleting Substances has triggered intensive efforts to qualify satisfactory replacement technologies. Alkaline cleaners have proven effective for removal of many solids from simple part shapes, but no previously published work has addressed the problem of cleaning manufacturing process soils from complex hollow turbine airfoil cooling passages. This paper will present a detailed study of cleaning effectiveness for a variety of soils, part configurations and mechanical assist technologies. Conclusions are drawn regarding appropriate cleaning systems for specific applications. Data should be applicable to the general problems of cleaning complex geometries.
4:30 p.m.--Lessons Learned in the Application of Plasma Spray Coatings on Jet Engine Parts
Dominic Varacalle, Vartech Inc.; Walter Riggs II, TubalCain Company, Inc.; & John Figert, Jack Worthington, Mark Syma & Domingo Carillo, Kelly Air Force Base, San Antonio, TX
Application of optimum coatings on jet engine parts requires a combination of proper equipment, appropriate materials, verified process parameters and auditable laboratory coating evaluations. At Kelly AFB, a complete process review of tungsten carbide coating applications was performed. The valuable lessons learned will be shared at the Forum.
5:00 p.m.--Panel Discussion, Flame Spray Coatings
Moderator: Donald Parker, Naval Aviation Depot, NAS, Jacksonville, FL Panelists: Dominic Varacalle, Vartech Inc.; Daniel Greving, The University of Tulsa, Tulsa, OK; Peter Kutsopia, Tafa; and other industry experts to be announced.
Thursday, May 2
7:30 a.m.--Solvent Reduction Processes in Place in the Aerospace Industry
William Stinson, Jr., William Spears, Jim Shank & Ken Colbert, Church & Dwight Co., Inc., Princeton, NJ
A sodium-bicarbonate-based cleaning process--an environmentally safe product--has been used successfully by American Airlines, Kelly Air Force Base and Allied Signal to clean and de-paint aircraft components, thereby eliminating hazardous solvents. This paper will discuss the appropriate hardware set-up and the process used, as compared to the previous cleaning/ de-painting processes (such as solvents, hand-cleaning, and, in some cases, scrapping of the parts). Sodium bicarbonate is a soft abrasive, 2.8 on the Mohs hardness scale, which offers flexibility to clean any surface, including those having an anodized coating. At 7.8, the pH of sodium bicarbonate enables it to be a good grease cleaner and a buffer for waste treatment systems.
8:00 a.m.--Automated Ultra-High Pressure Waterjet Process Applications
Arthur Fricke & Frederick Lancaster, Concurrent Technologies Corp., Johnstown, PA
Automated ultra-high-pressure waterjet (UHPWJ) systems are used to strip surfaces with a low-volume (1-3 gal/ min) pure water stream at pressures of from 35,000 to 55,000 psi. The stream is shaped by specialized nozzles that can modify it to achieve effects ranging from a relatively gentle, layer-by-layer removal of organic paints to the removal of tough flame-sprayed metal coatings. The nozzle-end effector assembly is manipulated by a six-degree-of-freedom (6-DOF) industrial pedestal robot, which is managed by a microprocessor-driven controller. The entire system is enclosed in a modular, waterproof workcell with subfloor drainage to allow for water reclamation and recycle. The reclamation system provides clean, particle-free water that is reused for blasting. The original solid paint or coating residue is the only waste associated with this process, and a small makeup water stream is the only raw material feed needed. Through a project sponsored by the National Defense Center for Environ-mental Excellence (NDCEE), Concur-rent Technologies is evaluating the performance of UHPWJ in removing coatings from helicopter and jet engine components, road wheels, engine cans, guided missile parts, and many other defense-related parts. The project involves close work with Department of Defense
(DOD) depots in the evaluation of test parts for stripping time, effectiveness and substrate damage in order to ascertain the applicability of UHPWJ to various commonly stripped components. Data is also being collected on operation, maintenance and other costs associated with UHPWJ. This work will eventually lead to accurate process and economic models for the UHPWJ system. The models can then be used to target specific areas in DOD and industry operation in which UHPWJ can effect great savings in time, energy and/ or hazardous process discharges. This paper will give an overview of process and economic information gathered to date, outline current and anticipated work, and give preliminary conclusions as to where and how this pollution prevention coatings removal technology can be applied.
8:30 a.m.--Vapor Degreaser Replacement for Removing Fluorescent Penetrants from Aerospace Castings
TBA, Proceco Ltd., Montreal, Quebec, Canada
In 1991, RG Hanson Co., Inc., a representative of PROCECO Ltd., began work with Howmet Corporation of LaPorte, IN to develop a process to replace 1,1,1-trichlor in the fluorescent penetrant inspection area. The new replacement process could not include the use of alkaline solutions, because the fluorescent penetrant agent is oil-based and the alkaline solution would potentially mask defects by preventing the agent from flowing into the defect, and would also affect the repeatability of the test on repaired castings. This meant that the agent would have to be broken down by some other type of media. After several tests, using a variety of pressures and temperatures, it was apparent that higher temperatures at lower pressures produced the desired results. The best result was achieved by running the casting at 50 psi and 260 ° F. At these conditions, in which the water became steam, no masking occurred after repeated cleaning. Once it was determined that steam would clean the casting without the use of chemicals, work began on developing a cabinet that incorporated a steam generator, fixed and movable manifolds, and a variable speed turntable to hold parts during cleaning. The equipment has now been operational for more than a year, removing fluorescent penetrant without 1,1,1-trichlor or alkaline chemicals.
9:00 a.m.--Al/Ceramic Overlay Coatings for Compressor & Al/Si Diffusion Coatings for Turbine Parts Containing Low Cr +6
Dr. Martin Thoma, MTU Deutsche Aerospace, Munchen, Germany
Al-ceramic coatings are well-known as corrosion-protective overlay coatings on compressor parts up to 600 °C. They are applied by a spraying technique. While the available '"'paints'"' contain a lot of chromic acid, low Cr +6 paints have been developed and tested. A similar coating with Al and Si is sprayed and then diffused for hot corrosion protection of turbine parts. Because the coating can be applied very easily, either locally or totally, it is useful for repair of damaged areas or for closing cooling holes to desired dimensions or as a hot corrosion protective coating, superior to Al-diffusion coatings done by the pack process. Various coating combinations can be tailored for specific applications. The coatings have been engine-tested, with excellent results in engine operation.
9:30 a.m.--Long-delay Hydrogen Embrittlement Phenomena By Plating High-Strength Steel Components
Dr. W. Paatsch, Federal Institute for Materials Research & Testing (BAM), Berlin, Germany
Electrochemical pretreatment, as well as plating processes of especially low-alloyed, high-strength steel, can be followed by hydrogen embrittlement. This applies to conventional zinc plating and also to the new zinc alloy coatings often used as a replacement for cadmium. The long delay embrittlement behavior of Zn- and Zn-alloy-plated guard rings was investigated. This phenomenon can be significantly correlated with the pickling procedure and the post-coating treatment. Further influence concerning the surface roughness, texture and morphology of the components can be observed. The mechanism seems to be of electrochemical nature, influencing the rate of atomic hydrogen evolution during the plating process. A test procedure to avoid long delay embrittlement has been evaluated.