Research focused on operating jet engines to withstand higher mechanical stresses at ever increasing temperatures has led to the development of Superalloys for components operating in these extreme conditions. The improvement in mechanical strength of Superalloys has been achieved however at the expense of resistance to oxidation and hot corrosion performance. To restore the resistance to oxidation and hot corrosion properties of jet engine components, the industry has developed a series of coatings. These coatings may be either, diffusion coatings of Aluminium or Platinum Aluminium which can stand alone or may be combined with a Metal Chrome Aluminium Yittrium (MCrAlY) overlay coatings.
Original Equipment Manufacturers (OEM) are now specifying Platinum Aluminide (PtAl) diffusion coatings in preference to simple Aluminium diffused coatings to give improved oxidation and hot corrosion resistant coatings for high pressure turbine components. Consequently, the Maintenance, Repair and Overhaul (MRO) industry also needs to provide these coatings as part of their engine overhaul capabilities.
Companies offering this service quite often experience difficulties in the following areas:
- Obtaining a consistent good quality deposit which will ultimately result in a satisfactory diffused Platinum Aluminide coating.
- Controlling deposition speed in order to accurately predict plating times for every run.
- Reconciling Platinum usage to levels of over 70% return on input.
Neil Cremin was invited by a client company, which installed a Platinum Plating line, to provide technical assistance and support to:
- Complete the commissioning of the Platinum Plating Line hardware and software installation.
- Validate the User Requirements Specifications (URS).
- Validate that each of the products to be electroplated complies with the specifications of the OEM.
- Draft procedures and checklists for operating the plating line to ensure consistent quality and compliance with specifications.
- Design training programmes to train operators, engineers and managers on the chemical, technical and operative aspects of the Platinum Plating Line.
The outcome of the project was that the company was operating a Platinum Plating process producing consistent and predictable quality product validated to meet the requirements of the specifications of the Original Equipment Manufacturer. With respect to the monthly reconciliation of Platinum metal usage, Neil achieved “best in class” results where the reconciliation was consistently over 90% and well in excess of the industry average. Finally all crucial aspects of the project were outlined in a Training course for Engineers and Operators covering the following topics:
- Introduction to the Principles of Electroplating
- Atomic Structure and the Reaction of Chemicals
- Electroplating of Platinum
- Plant and Process Control
On completion of the project, the company issued a testimonial on their experience of the service provided.