The physiologist, physicist and anatomist from Bologna, Luigi Galvani, became famous for his discovery of the electrical properties in living beings, but he also invented the electrochemical process of galvanization. Two centuries since his discoveries, the electrochemical processes he was the first to study are now fundamental to the mechanical engineering industry and are widely applied in various sectors for the processing of metals. Aviation is, without question, one of these sectors. In Avio Aero, for example, the production cycle also includes special processes, such as heat treatments, plasma treatments and, of course, galvanization.
Recently, even the Galvanic area in Rivalta di Torino, where the Avio Aero headquarters are located, has follow the path of industrial digital transformation. An application called "Digital Galvanic" has been developed in this department. This application involves an online tool whose purpose is to facilitate and improve the work of technicians and engineers in the department. The Digital Galvanica app is combined with several other solutions implemented in Avio Aero facilities, as well as in GE Aviation facilities spread across the world, and which have been developed on Predix, the GE industrial cloud technology platform. The same Rivalta team, which has developed tools such as Smartshop, dedicated to the real time monitoring of production lines and cells in 3 facilities, has also worked on this digital solution for Galvanica.
"We began to work on this about a year ago together with EKA, one of our partners in the Digital Technology environment," explained two IIoT experts ( Industrial Internet of Things), Matteo Longo, Brilliant Factory IT Engineer, and Giulio Marino, GSC Digital Engineer. "The implementation of the app in the test phase began in November 2017, and the objective, shared with production specialists, was focused on the maintenance of the galvanic tanks: to digitize the department to track prevention activities, support non-compliance management, improve performance, optimize time management, costs and communication between the analysis laboratory and the Galvanic department."
Galvanica is a rather large department in the facility, containing eight lines dedicated to chemical and electrochemical processes (these are the main and widespread processes), and a separate line where chemical attacks are carried out in preparation for non-destructive testing. Each line consists of a succession of tanks with a system of immersion and extraction of aircraft engine parts whose metal surfaces are subjected to essential chemical and electrochemical processes. "The gears of the power or accessory control drive trains, the casings or housings – which contain the engine modules – are the product categories which we treat here. To provide an idea, with regard to the gears alone, we are able to treat over two thousand units each month," explains Luigi Melchiorre, the Production Quality Assurance Specialist for the department. Another significant figure is the number of tanks, which totals 60 across 9 lines. These tanks contain chemical solutions that must comply with specific parameters (the measurement of acidity or alkalinity, the concentration levels of the elements or chemical compounds, etc.)
"What we do here," continues Melchiorre, attempting to make it easier to comprehend, "is treat the surface areas of the aluminum and magnesium housings to increase their resistance to corrosion; or we apply a temporary protective coating to the gears for later heat treatments or even carry out a chemical attack in preparation for non-destructive tests." Suggestive technical terminology and scientific nomenclature which transmit the true importance of this step in the production process: the parts subjected to galvanic treatment arrive from mechanical processes and are later subjected to further processes. The material used to manufacture the parts must meet the design requirements, and must also have the physical properties capable of meeting the demands of hours and hours of flight, very high temperatures and speeds. Galvanic is also a highly complex area where skilled and qualified professionals work according to stringent Environmental Health & Safety requirements in the workplace.
The scientific relevance of this area of the factory is confirmed by the close collaboration with the Analysis Laboratory which is a function of various industrial processes, and crucial for the galvanic process. Laboratory analysts, such as Andrea Sola and Samantha Capobianco at Rivalta, are involved in the cyclical sampling and testing of the metal alloys used in products, and the analysis of chemical solutions contained in the tanks in which these products are immersed and treated. From the laboratory technicians, we are able to understand the added value provided by the digital solution in the department. "The Laboratory is a fair distance from the department, but since the introduction of this app, it is as if we have camera monitoring line number 7 for 24/7."
Galvanic line 7 is, in fact, the line which is the "pilot", the first to be installed with the app: a screen mounted above the input to the line displays the graphic interface through which the line and tank operators, as a result of the typical green, yellow, red semaphore code are able to check the real time condition of the chemical solution and the concentration levels. The operators and Quality Control operators in the department are able to proceed with the "chemical baths" (the immersion of engine parts) confidently in the knowledge that the tanks are shown as green on the display, while they will take corrective action even if only one of these is displayed in yellow. It is the tank operator, in fact, alongside the process specialist who promptly adjusts the chemical solution contained in the tank to return the solution to its optimum operating condition and, once again, the color green is displayed on the screen. If, instead, a tank is displayed in red based on the data entered by the Laboratory, the tank must be shut-down, and any processes which are in progress must be stopped. In fact, the metal of the part immersed in that solution could be damaged.
At this point, the benefits provided by the app are easy to understand: the app makes it possible to anticipate problems, avoid waste and, therefore, reduce costs. But there is more. It is impressive to think that "the management of galvanic tanks was first carried out using an excel sheet which contained the formulas used to calculate the chemical solutions," explains Melchiorre. "The Laboratory sent the results of the analysis by e-mail; I manually copied the data onto the Excel file and calculated the possible correction that was then communicated via e-mail to the operators. All of this is now performed with a single click on a unique web-based solution. The operators receive the information in real time just through watching the display. In addition, the system is able to process multiple scenarios and specific situations for each tank, and suggest the most suitable corrective action to take for each of these scenarios. Each corrective action has been defined based on technical skill, but also on the tricks of the trade which are learned through experience. Suffice it to say that, in the past, I would dedicate 45 minutes to these calculations, up to about an hour a day: for line 7, it now takes three minutes at most."
The app is available on Predix, an advantage which will make it more widespread in the future via GE Store, and it is online as well, ensuring direct sharing between the Laboratory and the Galvanic department. Furthermore, the results in terms of time and costs are destined to increase considering that by the end of the year; the remaining eight lines will adopt this solution. An annual savings of 426 hours has, in fact, been calculated (approximately equal to 14,000 euros) on line 7. This could rise to 720 hours annually (equal to 80,000 euros) by preventing the shut-down of all tanks on the lines.
All of which is time earned for the team as well, which will maybe allow more sport to be enjoyed during the break: why not go for a swim, even? And not in a tank, of course!Author: Anna Zovetti & Patrizia Carato