Cleaning Retaining/Sealing Rings (Superalloy NIMONIC 90) with Ultrasonic Cleaning
The cleaning of retaining/sealing rings is a critical step in ensuring the quality and functionality of these components. Proper cleaning is essential to remove any vibratory residues before the application of PVC coatings, ensuring a clean and smooth surface that can perform reliably under demanding conditions.
The cleaning process is conducted using a K Sonic 30 benchtop ultrasonic cleaner, which provides the necessary agitation for removing contaminants. Rodastel 30, an acid-based liquid detergent, is used for its effectiveness in deoxidation, neutralisation, and activation of surfaces prior to vacuum coating. Tap water is employed for the initial rinsing, while deionised (DI) water is used to ensure a spot-free finish by removing any remaining minerals. For the final drying step, a Versa Genius+ 120 hot air dryer is utilised to eliminate moisture from the components.
The process begins by filling the ultrasonic cleaning tank with tap water, into which a 3% concentration of Rodastel 30 cleaning fluid is added. This acidic solution is heated to a temperature of 50°C to enhance its effectiveness. The five NIMONIC 90 rings are then suspended in a wash basket, ensuring they remain submerged in the solution throughout the cleaning cycle. The ultrasonic cleaning process runs for five minutes, allowing the Rodastel 30 to penetrate and break down any vibratory residues present on the rings' surfaces. The ultrasonic agitation further aids in dislodging contaminants, ensuring thorough deoxidation and surface preparation.
After this initial cleaning step, the rings are transferred to a separate tank containing tap water at 20°C. This two-minute rinse serves to remove any residual traces of Rodastel 30 from the components. The use of tap water effectively washes away detergent residues, preparing the rings for the next phase of rinsing without introducing additional contaminants.
The rings are then placed in a tank filled with DI water, which is heated to 60°C. This final rinse is critical as it removes any remaining mineral content from the tap water, ensuring that the surface of the rings remains spot-free. DI water's purity prevents the formation of water spots that could affect the quality of subsequent coatings. This step not only ensures a clean surface but also readies the rings for drying by eliminating any potential water-related imperfections.
The cleaned rings are then dried using the Versa Genius+ 120 hot air dryer, set to a temperature of 70°C. The drying cycle lasts for five minutes, during which hot air circulates around the rings, evaporating any remaining moisture. This ensures that the rings are thoroughly dried, free from water residues, and ready for further processing or coating applications. The drying step is crucial in preventing any water-based defects that could affect the rings' performance in service.
The overall cleaning process integrates several key parameters to achieve effective decontamination. Rodastel 30 is used at a 3% concentration, with the initial cleaning solution maintained at 50°C. The tap water rinse occurs at 20°C, while the DI water rinse is performed at 60°C. The final drying stage involves heating the rings at 70°C for five minutes, ensuring complete removal of any moisture. This combination of steps results in thoroughly cleaned and prepared retaining/sealing rings that are ready for the next stages of manufacturing or coating.
Before and After
